Chapter III: Their Form of Prescription (2)

M. de qua sumatur cochl: unum minimum ex cyatho Infus: Anthemid: Flor: ter quotidie.

_Emmenagogue and Antispasmodic._

98. ℞. Pil: Aloes cum Myrrha
et
Pil: Galbani comp: āā ʒj =B.=

Divide in Pil: xxiv, e quibus sumantur binæ bis quotidie.

99. ℞. Pill: Aloes cum Myrrha
et
Pil: Ferri comp: āā ʒj =G.=1.
Sodæ Sub-Carbonatis ℈j =G.=2._l._

Divide Massam in Pilulas xxx e quibus sumantur binæ bis quotidie.

DIURETICS.

100. ℞. Scillæ Radicis exsiccat: gr. iij
Pulveris Opii gr. ss =C.E.=
Cinnamomi Corticis gr. x =E.O.=

Fiat pulvis bis quotidie sumendus.

101. ℞. Potassæ Sub-Carbonatis gr. x
Infus: Gentian: comp: f℥iss =C.N.=
Spir: Etheris comp: fʒss =B } G.E.=
Træ Cinnamomi fʒi =}=

Fiat Haustus.

_Diuretic and Stimulant._

102. ℞. Scillæ Radicis exsiccat: gr. xij
Potassæ Nitratis ʒi =F.=
Sacchari purificat: =B } M.E.=
et Cinnamomi cort: contrit: =}=

āā ʒi. fiat pulvis in sex partes æquales dividend: Sumatur una bis indies.

103.[317] ℞. Scillæ Rad: exsiccat: gr. iv
Digitalis Foliorum gr. x =B.=
Hydrargyri Sub-muriat: gr. vj =C.=
Myrrhæ Pulv: ℈i =}=
simul tere et adde =B. } G.=
Assafœtidæ ʒss =}=
Extract: Gentian. q. s. =C. O.=

Fiat massa in Pilulas xv dividend: e quibus sumatur una, nocte maneque.

104. ℞. Massæ Pil. Scillæ ʒi
Hydrarg: Sub-muriat: gr. v =C.=

Fiat massa in Pilulas xv dividenda, quarum sumantur duæ singulis noctibus.

105. ℞. Sodæ Carbonat: exsiccat: ʒi
Saponis duri ℈iv =N.B.=
Olei Juniperi =F.E.=
Syrupi Zingiberis q. s. =E.N.=

Fiat massa in Pilulas xxx dividenda, e quibus capiat tres, indies, contra calculos renum.

_Beddoes._

106. ℞. Scillæ Radicis exsiccat: gr. ij
Pilulæ Hydrargyri gr. v =G.C.=
Opii gr. ss =E.C.=

Fiat Pilula hora decubitus per tres vel quatuor noctes consequentes capienda.

107. ℞. Potassæ Sub-carbonat: ℈i =}=
Succi Limonum: f℥ss, vel q. s. =I. } K.=
Aquæ Cinnamomi f℥i =}=
Aceti Scillæ fʒiss =B.=
Tinct: Opii ♏︎v =C.=
Syrupi Aurantii fʒss =O.=

Fiat Haustus bis indies sumendus.

108. ℞. Potassæ Acetatis ʒi
Oxymel; Colchici fʒij =B.=
tere simul cum aquæ puræ f℥i =N.=
Spir: Juniperi comp: f℥ss =B.O.=

Fiat Haustus, ut supra dandus.

109. ℞. Baccarum Juniperi contus: ʒij
Semin: Anisi contus: ʒij
Aquæ: ferventis oj

Macera per tres horas, dein cola.

℞. Colaturæ f℥xij =A. }=
Spir: Junip: comp: f℥ij =}=
Træ Scillæ fʒi =B.=
Potassæ Nitratis ℈ij =F.=

Fiat Mistura, de qua sumatur cyathus subinde.

110. ℞. Infus: Digitalis f℥iv =A. }=
Træ Digitalis fʒss =}=
Potassæ Acetat: ʒi =B.=
Tinct: Opii ♏︎v =C.E.=

Fiat Mistura, de qua sumatur coch: unum amplum bis terve indes.

111. ℞. Liquoris Ammoniæ Acetat: f℥ss
Potassæ Acetatis ʒi =B.=
Aquæ puræ f℥j =N.O.=

Fiat Haustus ter quotidie sumendus.

112. ℞. Potassæ Supertartratis ʒi
Pulveris Scillæ exsiccat: gr. iij =B.=
Pulveris Zingiberis gr. v =E.=

Fiat pulvis, sexta quaque hora capiendus.

113. ℞. Spartii cacum: concis: ℥i
Aquæ puræ oj

Decoque ad octarium dimidium, et cola.

℞. Colaturæ f℥i
Spir: Etheris Nitrici ♏︎x =B.E.=

Sumatur alternis horis.

114. ℞. Tinct: Ferri Muriat: ♏︎xv
Infus: Quassiæ f℥i =C.N.=

Fiat Haustus tertia quaque hora sumendus.

115. ℞. Potassæ Nitratis ʒi
Misturæ Ammoniaci f℥vj =N.=
Spir: Juniperi comp: f℥iss =B. } B.E.=
Aceti Scillæ fʒvi =}=

Fiat Mistura de qua capiat cochl: j amplum quartis horis.

116. ℞. Tincturæ Lyttæ ♏︎x
Spiritus Ætheris Nitrici fʒi =F.=
Misturæ Camphoræ fʒxij =E.N.=
Syrup: Zingiberis fʒi =E.O.=

Fiat Haustus ter in die sumendus.

_a highly stimulating diuretic._

DIAPHORETICS.

117. ℞. Misturæ Camphoræ fj℥ss
Liquor: Ammon: Acet: f℥ss =F.=
Liquor: Antimonii Tart: ♏︎xx =H. } B.=
Tinct: Opii ♏︎x =}=

Fiat Haustus.

118. ℞. Potassæ Sulphureti gr. xv
Saponis duri ʒj =E.L.=
Balsam: Peru: q. s. =O.=

Ut ft: Pilulæ xxx; sumat tres quarta quaqua hora ex cyatho Infusi calidi Juniperi baccarum.

_In Cutaneous Affections._

119. ℞. Pulveris Antimon: ʒss =}=
Opii Pulv: ℈ss =H. }=
Hydrargyri Sub-muriat: gr. v =}=
Confect: Opii q. s. =O.B.=

Ut fiant Pilulæ decem, quarum capiat unam hora decubitus, et repetatur p. r. n.

120. ℞. Pulveris Ipecacuanhæ comp: gr. xv.
Pulv: Trag: comp: ℈ij =N.=

Divide in partes quatuor æquales, quarum sumat unam omni hora.

121. ℞. Pulv: Ipecacuanhæ comp: gr. xv
Pulv: Antimon: gr. ij =B.=

Ft: pulvis, hora decubitus sumend: superbibendo Haustulum tepidum.

122. ℞. Guaiaci gum-resinæ gr. x
Pulv: Ipecacuanhæ comp: gr. v =F.=
Confect: Rosæ q. s =O.=

Ut fiat Bolus, h. s. sumendus.

123. ℞. Potassæ Carbonatis gr. x =}=
Mist: Camphoræ: f℥j =I.K. }=
Ft: Haust: cum Succi Limonum =}=

Cochleari uno amplo, in impetu ipso effervescentiæ sumendus.

124. ℞. Guaiaci gum-resinæ gr. x
Antimonii Tart: =}=
et =H. } B.=
Opii puri āā gr. j =}=
Syrupi q. s. =O.=

Fiat Bolus bis quotidie sumendus.

125. ℞. Camphoræ
et Pulveris Antimon: āā gr. iij =H. } F.=
Opii puri gr. j =}=
Confect: Aromat: q. s =N.=

Fiat Bolus, h. s. sumendus.

126. ℞. Liquor: Ammoniæ Acetat: fʒij
Decoct: Cinchonæ fʒx =A. } G.=
Tinct: Cinchonæ fʒij =}=
Confect: Aromat: ʒss =N.=

Ft. Haustus, tertia vel quarta quaque hora sumendus.

127. ℞. Guaiaci gum-resinæ ʒij
Acaciæ gummi ʒij =M.=
Simul bene tritis adde
Træ Opii fʒss =C.=
Pulv: Cinchonæ ʒj =}=
Træ Cinchonæ fʒij =A. } G.=
Decoct: Cinchonæ f℥viij =}=

Fiat Mistura cujus sumatur cyathus bis quotidie.

_Rheumatism._

128. ℞. Extracti Aconiti
Antimonii Sulphureti =}=
Præcipitati āā gr. j. =E. } B.=
Magnesiæ Carbonatis ℈ss =}=

Tere simul ut fiat pulvis.

129. ℞. Pulv: Antimon: gr. iij.
Potassæ Sub-carbonatis gr. v. =E.=
Anthemid. Flor. exsiccat: ℈j =N.=

M. Fiat Pulvis sexta quaque hora, per biduum vel triduum sumendus.

130. ℞. Pulveris Ipecacuanhæ gr. ij =H. }=
Pulveris Opii gr. i. =}=
Potassæ Nitratis gr. xvj. =M.F.=

Fiat Pulvis hora somni sumendus.

EXPECTORANTS.

131. ℞. Assafœtidæ ℈ij
trituratione solve in
Aquæ Menthæ vir: f℥iij. =N.=
addeque Syrup: Tolu: f℥j =G.=

Fiat Mistura, de qua sumatur cochl: unum amplum tertia quaque hora.

132. ℞. Myrrhæ gum-resin: ʒss
Sacchari purificati ℥ss. =M.=

Tere optime simul ut fiat Pulvis, partitis dosibus quotidie sumendus, in vehiculo aliquo idoneo.

133. ℞. Myrrhæ gum-resin: ʒiss
Scillæ exsiccat: ʒss =B.=
Extract: Hyoscyami ℈ij =G.=
Aquæ q. s. ut fiant Pil. xxx. =N.O.=

E quibus sumantur binæ, nocte maneque.

134. ℞. Scillæ exsiccatæ gr. viij
Pulveris Ipecacuanhæ gr. v =C.=
Camphoræ ℈j =G.=
Pulv: Antimon: gr. vj =C.=
Sacch: purificat: ʒj =M.=

Tere in pulverem, in quatuor partes æquales dividendum. Pars una sumatur bis quotidie, ex haustu decocti hordei.

135. ℞. Oxymel: Scillæ
Syrupi Altheæ =B. } F.=
Mucilag: Acaciæ =}=

āā f℥ss, misce, et fiat linctus, de quo lambat sæpe.

136. ℞. Misturæ Ammoniac:
et Aquæ Cinnamomi āā f℥iss =N.=
Syrupi Tolut: f℥ss =N.O.=
Tinct: Castorei fʒij =B. } G.=
Tinct: Opii ♏︎v =}=

Fiat Mistura, cujus sumatur Cochl: unum amplum subinde, ac repetatur dosis p. r. n.

_Expectorant & Antispasmodic. Hooping Cough, &c._

137. ℞. Mist: Amygdal: f℥j
Vini Ipecacuanhæ ♏︎x =G.=
Potassæ Carbonatis gr. x. =I.K. } G.=
Sumatur cum Succi Limon: fʒiij =}=

In impetu ipso effervescentiæ.

138. ℞. Pulveris Myrrhæ gr. xij
Pulv: Ipecacuanhæ gr. vj =F.=
Pulv: Potassæ Nitrat: ʒss =E.=

Misce et divide in doses æquales quatuor, quarum sumat unam quartis horis.

139. ℞. Tinct: Scillæ ♏︎x
Acid: Nitric: dilut: ♏︎vj =C.=
Extract: Hyoscyam: gr. iij =G.=
Aquæ puræ f℥iss =N.=

Fiat Haustus tertiis horis sumend:

_Bree._

140. ℞. Acid: Nitric: fʒj =}=
Aquæ puræ f℥iv misce =} H.=
dein tere cum =}=
Ammoniaci ʒj =}=
donec emulsio evadit

Dosis cochl: j medioc: ex liquore aliquo demulcenti.

SIALOGOGUES.

141. ℞. Hydrarg: Oxyd: rubri gr. j.
Opii tertiam grani partem =C.=
Caryophyll: olei ♏︎j =E.=

Fiat pilula, h. s, per hebdomadam sumenda.

_J. Hunter._

142. ℞. Hydrarg: oxy-muriat:
Ammoniæ muriat: āā gr. v =L.=
Aquæ distillat: fʒss =N.=
Glycyrrhizæ rad: contrit: ℈iv =B. } O.=
Mellis ʒss =}=

Cogantur in massam, quam divide in pil: xl, e quibus sumatur una ter die.

143. ℞. Pyrethri rad: contrit
Mastiches āā ʒj =M.N.=

Fiant lege artis, ad ignem, masticatoria duo; teneat æger sœpius in ore, et manducet hujusmodi medicamentum, exspuatque salivam.

_Hartman._

REFRIGERANTS.

144. ℞. Potassæ Nitratis gr. xv

Ft: Pulv: ex cyatho Aquæ perfrigidæ, illico post solutionem sumend:

145. ℞. Acidi Muriatici fʒj
Decoct: Hordei oj =N.=
Syrupi fʒij vel q. s, =O.=

ad acorem compescendum, et gustum conciliandum. Sumatur quotidie, instar potus, et bibat quantum sitis exigat.

_In Typhus and other Fevers._

146. ℞. Ammoniæ Muriat: ʒij
Acidi Acetici dilut: f℥ij =B.=
Spir: Camphor: f℥ss =G.=

Misce ut fiat Lotio.

147. ℞. Liquor: Plumbi Sub-acetat: fʒj
Acidi Acetici dilut: f℥ij =L.=
Spir: tenuior f℥ss =G.=
Aquæ destillatæ f℥viij =N.=

Fiat lotio.

148. ℞. Liquor: Ammon: Acetat: f℥vj
Spir: Rosmarini f℥ij =G.=
Aquæ puræ oj =N.=

Sit pro Epithemate, capiti raso applicandum.

ANTACIDS AND ABSORBENTS.

149. ℞. Liquoris Potassæ fʒij
Liquoris Calcis f℥vj =F.N.=

M. Cujus capiat æger, acido infestante, cochleare amplum unum, vel alterum, ex poculo jusculi bovini.

150. ℞. Magnesiæ ʒss
Aquæ Menthæ Pip: fʒiiss =}=
Spir: Lav: comp: fʒss =B. } G.=
Spir: Carui fʒiv =}=
Syrup: Zingib: fʒij =}=

Sumatur cochleare unum mediocre, p. r. n.

_Antacid and Carminative._

151. ℞. Pulv: Cretæ co: cum Opio ℈j
Pulv: Catechu Extract: gr. xv =G.=

Sit pulvis, post singulas sedes liquidas sumendus.

_In Diarrhœa depending upon Acidity._

152. ℞. Ammoniæ Sub-carb: gr. v.
Extract: Rhei gr. viij =G.N.=

Fiat massa in Pil: binas dividenda.

153. ℞. Magnesiæ Sub-carbonat: gr. v
Sodæ Sub-carb: gr. v =B.=
Zingib: rad: contrit: gr. iv =E.=
Glycyrrhizæ rad: contrit: gr. xv =M.O.=

M. et fiat pulvis, contra cardialgiam.

ANTILITHICS AND LITHONTHRYPTICS.

A. _In the Lithic Acid Diathesis._

154. ℞. Sodæ Sub-carb: gr. x
Infus: Quassiæ f℥j =G.C.=
Tinct: Calumbæ =E.=

Fiat Haustus bis quotidie sumendus.

155. ℞. Magnes: Sub-carbonat: ℈j
Infus: Calumbæ f℥j =A. } G.C.=
Tinct: Calumbæ fʒj =}=

Fiat Haustus.

156. ℞. Sodæ Sub-carbonat: gr. x
Mist: Amygdal: f℥j =N.O.=
Balsam: Copaib: (ope mucilag: mist:) fʒss =G.=1.
Tinct: Opii ♏︎v =G.=2.

Fiat Haustus, urgenti dolore sumendus.

157. ℞. Magnesiæ Sub-carbonat: gr. x
Pulv: Ipecac: gr. j =G.=
Sodæ Sub-carbonat: gr. v. =F.=

Fiat Pulvis, ex vehiculo aliquo idoneo sumendus; superbibendo cyathum Infusi Anthemid: Flor:

B. _In the Phosphatic Diathesis._

158. ℞. Acid: Muriatic: ♏︎v
Decoct: Hordei comp: f℥iss =N.=

Fiat Haustus ter quotidie sumendus.

159. ℞. Infus: Ros: f℥iss
Magnes: Sulphat: ʒj =G.=
Tinct: Calumbæ fʒij =E.=

Fiat Haustus.

ANTHELMINTICS.

160. ℞. Stanni Limat: ℥iij
Confect: Rosæ Gall: ℥ss =B. } N.=
Syrupi q. s. ut fiat Elect: =}=

Capiat coch: amplum, quotidie mane, et repetatur dosis ad tres vices, et deinde capiat æger Haustum aliquem purgantem.

161. ℞. Cambogiæ g. viij
Hydrarg: Sub-muriat: gr. v =F.=

Mucilag: Acaciæ q. s. ut fiat Bolus mane sumendus.

_Contra Tæniam._

162. ℞. Sodæ Muriatis ℥ij
Coccinell: ℈ij =M.O.=

Fiat Pulvis, et detur drachma dimidia pro dosi, tempore matutino.

163. ℞. Ferri Sub-carbonat: ℈j

Sumatur ex vehiculo aliquo crasso, singulis auroris.

164. ℞. Camphoræ (Alcohole solutæ) ʒj
Ol: Olivæ fʒij =L.N.=

Misce, Fiat Enema.

Injiciatur h. s. tertia quaque nocte, ad tres vices: dein repetatur alternis noctibus, ad quartam usque vicem, si opus fuerit.

_Contra Ascarides._

165. ℞. Aloes Spicat: gr. x
Saponis Duri ʒj =L.N.=

Fiat Suppositorium post Alvum exoneratam applicand.

DEMULCENTS.

166. ℞. Olei Amygdal: f℥j
Acaciæ gummi ʒiij =M.N.=
tere simul, et dein gradatim adde
Aquæ destillatæ f℥vi =O.=
Syrup: Rhæados f℥ss =O.=

Fiat Mistura, de qua sumantur Cochlearia duo ampla ter, quaterve, indies.

167. ℞. Olei Amygdal: fʒvj =I. }=
Liquoris Potassæ ♏︎L =}=
Aquæ Rosæ f℥viiss. =N.=

Fiat Mistura, ut supra capienda.

168. ℞. Mistur: Amygdal: f℥j =}=
Potassæ Carbonatis gr. x. =I.K. }=
Syrupi Rhæados fʒj =}=
Ft: haust: cum cochl: Succ: Limon: =}=

in impetu effervescentiæ sumend:

_Demulcent & Febrifuge._

169. ℞. Pulv: Cetacei
Pulv: Trag: comp: āā ℥ss =B.=
Syrupi Papaveris q. s. =N.O.=

Misceantur, et fiat Linctus. Dosis cochl: minimum subinde.

170. ℞. Cetacei ʒij
Pulv: Trag: comp: ʒj =}=
Syrup: Papaveris =B. } B.=
Syrup: Tolu: āā fʒij =}=
Confect: Ros: ʒvj =}=
Potassæ Nitratis ʒss =G.=

Fiat Electuarium, de quo capiat ad nucis moschatæ magnitudinem.

171. ℞. Cetacei ʒij
Vitelli ovi dimidium =}=
Syrupi f℥ss. =} B.=
Aquæ Cinnamomi f℥ij =}=
Aquæ destillatæ fʒiv =}=

Fiat Mistura, de qua capiat æger cochleare amplum frequenter.

172. ℞. Amyli ʒiij
Aquæ ferventis f℥iv. =L.=
Solve pro enemate, et adde,
si opus fuerit,
Tinct: Opii fʒss =G.=

173. ℞. Decoct: Lichenis oss
Sumatur quotidie, cochleatim,
instar potus communis.

SUPPLEMENTARY FORMULÆ
FOR CERTAIN REMEDIES
NOT INCLUDED IN THE PHARMACOPŒIA.

1. ℞. Acid: Hydro-cyanic: dilut: ♏︎v
Mist: Amygd: f℥iv =} O.=
Syrup: Tolutan: fʒj =}=

Fiat Mistura, de qua sumatur Cochleare unum amplum tertia quaque hora.

2. ℞. Acid: Hydro-cyanic: dilut: ♏︎xij
Tinct: Digitalis fʒss =F.=
Aquæ Cinnamom: f℥vss =O.=

Sumatur Cochl: unum amplum quartis horis.

3. ℞. Acid: Hydro-cyanic: dilut: fʒj
Aquæ Rosæ f℥iss

Sit pro lotione contra Impetigines utend:

4. ℞. Morphiæ Acetatis gr. xij
Aquæ destillat: f℥j =N.=
Acid: Acetic: dilut: ♏︎v =L.=
Spir: Rectificat: fʒj =P.=

Sumantur guttæ x–xx, ad dolorem leniendum, et somnum conciliandum.

5. ℞. Iodini ℈ij
Spir: Rectificat f℥j

Solve et fiat Tinctura.

℞. Tincturæ Iodini ♏︎v.
Aquæ destillat: f℥j =N.=

Sumr: guttæ x ter quotidie.

6. ℞. Quinæ Sulphat: gr. ij
Acid: Sulphuric: dilut: ♏︎ij =L.=
Aquæ destillat: f℥j

Fiat Haustus, bis terve de die sumend:

OF THE
MEDICINAL DYNAMETER.

This instrument is capable of showing, on mere inspection, the absolute as well as relative strengths of the different Officinal Preparations of the Pharmacopœia. The active Principles, or Medicinal Bases, are distinguished by CAPITAL LETTERS, placed in coloured compartments, and each Officinal preparation is marked by a line corresponding in colour with that of its active ingredient. Where a preparation contains two active ingredients it is distinguished by two coloured lines, as may be seen in the _Pulvis Ipecacuanhæ comp_. By this expedient the eye, at once, recognises the different classes of medicines; all those, for instance, coloured _red_ are Opiates; those _blue_, Mercurials; _green_, Acetic acid; &c. The introduction of colours, moreover, immediately indicates the basis to which any preparation refers, and thus prevents the possibility of doubt or confusion.

If we wish to learn the actual quantity of active matter contained in any given proportion of a compound, we have only to turn the scale until the name of such compound coincides with the number in question, when the figure opposite to the basis solves the problem; thus—how much opium is contained in 5 grains of the _Pulvis Ipecacuanhæ compositus_? By having brought this preparation to 5, we shall see ½ opposite to Opium, denoting that such a number of grains contains half a grain; for, unless it be otherwise expressed, the figures denote _grains_ for the solids, and _minims_ for the liquids. And, since the number opposite to the Base denotes the absolute quantity of it contained in those several proportions of its Officinal compounds, which are expressed by the respective numbers opposite to each, it follows that these latter must all be medicinally equivalent to each other; thus we have seen that 5 grains of _Pulvis Ipecacuanhæ compositus_ contains ½ grain of Opium, if we turn our eyes to the other Opiate preparations we shall perceive that each has a different number opposite to it, these figures show the number of grains of each which contains ½ grain of opium, and consequently those numbers must be all Equivalents; thus 2½ grains of _Pil. Saponis comp:_ 5 grains of the _Pulv: Corn: ust: cum Opio_, 9½ minims of Tinctura Opii, 10 grains of _Pulv: Kino comp:_ 18 grains of _Confectio Opii_, 20 grains of _Pulv: Cretæ comp: cum Opio_, and 120 minims, or two fluid-drachms of _Tinctura Camphor: comp:_ contain half a grain of Opium, and are consequently all equivalent to each other. This system of Equivalents will be found of much practical value to the practitioner, by enabling him, at once, to substitute one preparation for another, without the risk of altering the dose of its active ingredients. Suppose, for example, a patient had been taking 8 fluid-drachms of _Mist: Ferri Comp._ and that we wish to give the same quantity of Protoxide of Iron in the form of the _Pil: Ferri comp_. we have only to bring the mixture in question to 8, and we shall see 13½ grs. are equivalent, both these quantities of the respective preparations containing ⅔ds of a grain of protoxide, or a little more than a grain of the Proto-carbonate. Suppose again, that we have an acetic acid of sp. gr. 1.059, and that we wish to produce, by its dilution, two fluid-drachms, or any other quantity, of acid having the strength of distilled vinegar, the question is, what are the proportions of water and strong acid to be employed. We have only to bring the Acidum Aceticum of 1.059, to 120, i. e. to fʒij, and the number opposite to the strong acid, _viz._ 16, is its equivalent, if therefore we take 16 minims of it, and dilute it with 104 minims of water, we obtain the mixture required.

Those who are acquainted with the sliding rule of Gunter, or the chymical scale of Dr. Wollaston, will immediately perceive that the present circular scale is divided upon the same logometric principle, and that the mechanical addition and subtraction of ratios here performed by juxta-position, corresponds in effect to the multiplication and division of the numbers by which the ratios are expressed in common arithmetical notation. It is not necessary that I should trouble the reader with the numerous difficulties and embarrassments which have opposed themselves to the practical success of this instrument. They have, after repeated failures, been at length overcome, except perhaps with regard to a slight central error, which as it is found in the most accurate brass instruments, could not be avoided where pasteboard alone had been employed. The error, however, is not of the slightest practical moment, not occasioning the difference of a hundredth part of a grain.

The proportions of active matter, in the several preparations of each class, have been, in general, derived from the best authorities, although in many cases they have been deduced from experiments expressly instituted for the occasion.

PHARMACOLOGIA.

COMPREHENDING

THE MEDICINAL HISTORY AND CHEMICAL HABITUDES

OF THE

DIFFERENT ARTICLES THAT CONSTITUTE THE

MATERIA MEDICA.

“_Omnium Simplicium Pharmacorum vires nosse oportet cum qui aliquot
compositum est facturus._”

_Ætius._

PHARMACOLOGIA.

ABIETIS[318] RESINA. L. E. D. (Pinus Abies, _Resina concreta_.) _Resin of the Spruce Fir._

Olim, _Thus—Frankincense_.[319]

QUALITIES. _Form_, tears or small brittle masses: _Odour_, very fragrant when burning. It has all the chemical properties of a _Resin_, and is used only for external purposes: see _Pix Arida_. OFFICINAL PREPARATIONS. _Empl: Aromatic:_ D. _Empl: Galban: comp:_ L. _Empl: Opii_ L. _Empl: Thuris._ D.

ABSINTHIUM. (Artemisia Absinthium) _Common Wormwood._

QUALITIES. _Odour_, strong and peculiar. _Taste_, intensely bitter, slightly pungent, and very unpleasant, as its name[320] implies. CHEMICAL COMPOSITION. Extractive, a small portion of resin, and a green essential oil; in the first of which its bitterness resides, in the last, a narcotic principle; hence the watery extract is not possessed of the nauseous flavour of the plant but retains its bitterness almost entire; the narcotic principle is therefore dissipated by decoction, but its tonic and anthelmintic properties are not impaired by that process. MEDICAL USES. The whole plant is powerfully antiseptic; and its bitterness renders it stomachic. Infused in ale it forms the beverage known by the name of _Purl_. Its powers as a vermifuge has bestowed upon it the name of _Wormwood._ DOSE, ℈j, ℈ij; and of the infusion, (made in the proportion of ℥j of the plant to oj of water,) f℥i-f℥iss. INCOMPATIBLE SUBSTANCES. Precipitates are produced in the decoction or infusion by _Sulphate of Iron_, _Acetate of Lead_, and some other metallic salts. Tartarized Antimony is not in the least affected by it. OFF: PREP: _Extract: Absinth:_ D.

ACACIÆ GUMMI. L. (Acacia vera.) Mimosa. Nilotica. E. D. _Gum Arabic._

QUALITIES. It is dry, semi-transparent, brittle and insipid; by exposure to the air it undergoes no other change than loss of colour. _Specific Gravity_, 1·515. SOLUBILITY. It is soluble in water in every proportion, forming a viscid solution, (_mucilage_). One part dissolved in water affords a fluid of the consistence of syrup; and in two parts, a medium well calculated for the union of dry powders. Gum is also soluble in pure alkalies and lime water, as well as in vegetable acids, especially vinegar, with which it forms a mucilage that may be used as a cement, like the watery solution, and with the additional advantage of not being susceptible of mouldiness.[321] It is insoluble in alcohol, as well as in æther and oils. By strong sulphuric acid the gum is decomposed, and a considerable proportion of carbon deposited.[322] For a farther history of its habitudes see _Mucilago Acaciæ_. MEDICINAL USES. It is demulcent and nutritious; although it appears in certain states of the body to pass through the bowels without change. When triturated with gum-resins it assists their mechanical division, as in _Form: 30_. OFFICINAL PREPARATIONS. _Mucilago Acaciæ._ L. E. D. _Emulsio Mimosæ Niloticæ._ E. _Emulsio Arabica._ D. _Mist. Corn. ust._ L. D. (=O=) _Mist. Cretæ._ L. D. (=O=) _Mist. Moschi._ L. (=O=) _Confect. Amygdal._ L. (=O=) _Pulv. Cret. co._ L. (=O=) _Pulv. Tragacanth co._ L. (=B=) Trochisci _Carbonat. Calcis_ E. (=O=) _Troch._ _Glycyrrh. Glab._ E. (=O=) _Troch. Glycyrrh. cum Opio_ E. (=O=) _Troch. Gummos._ E. (=O=). ADULTERATIONS. Gum Senegal is not unfrequently substituted for it, but this may be distinguished by its clammy and tenacious nature; whereas genuine _gum arabic_ is dry and brittle; the fraud is of no consequence in a medical point of view. It is also occasionally mixed with the gum of plum and cherry trees; this fraud however, is to be easily detected, for such gum has peculiar properties by which it may be chemically distinguished; see _Mucilago Tragacanth_.

ACETICA. L.E.D. _Preparations of Vinegar._

These preparations consist of vegetable principles dissolved in vinegar. OFFICINAL PREPARATIONS. _Acetum Aromaticum._ E. _Acidum Acetosum camphoratum._ E. Medicated vinegars were formerly much extolled; the first London Dispensatory contained no fewer than ten, at present the number is reduced to two, viz. _Acetum Colchici._ L. _Acetum Scillæ._ L.E.D. _which see_.

ACETIS HYDRARGYRI. E. Acetas Hydrargyri. D. _Acetate of Mercury._

QUALITIES. _Form_, small flaky crystals; _Colour_, silvery white; _Taste_, acrid. CHEMICAL COMPOSITION. Acetic Acid, and Oxyd of Mercury. SOLUBILITY. It is soluble in hot, but very sparingly in cold water, and quite insoluble in Alcohol. FORMS OF EXHIBITION. It should be always given in pills,[323] it is however seldom used. DOSE, gr. j. As an external application, a solution of it, in the proportion of grs. j. to f℥i of rose water, has been commended as a cosmetic.

ACETOSÆ FOLIA. L.E. Rumex Acetosa.

_Common Sorrel Leaves._

QUALITIES. _Taste_, grateful, austere and acidulous. CHEMICAL COMPOSITION. All its qualities depend upon the presence of _Super-oxalate of Potass_. In France the plant is commonly cultivated for the use of the table.

ACETOSELLA. L. Oxalis Acetosella.

_Wood Sorrel._

The qualities of this plant, like those of the preceding, depend upon _Super-oxalate of Potass_.

ACETUM. L. _Vinegar._

Acidum Acetosum, E. Acetum Vini. D.

QUALITIES. Too well known to require description.[324] CHYMICAL COMPOSITION. Acetic acid largely diluted with water, vegetable gluten, mucilage, sugar, extractive matter, and frequently malic and tartaric acids, together with small proportions of sulphate of lime, sulphate of potass, and alcohol. Its composition however varies according to the fermented liquor from which it is obtained:[325] e. g. wine yields a paler, purer, and stronger acid than fermented malt liquors or solutions of sugar, hence the superiority of that prepared in France and Italy. Vinegar is liable to spontaneous decomposition, or to become mouldy, and consequently for the purposes of pharmacy it should be distilled; as however the change depends upon the presence of gluten, it may if boiled be kept for a much longer time, and if powdered _animal_[326] charcoal be previously added, it will become quite colourless like distilled vinegar, and that without being impaired in strength, whereas it always becomes much weaker by distillation. It is a curious circumstance that this is the only vegetable acid, except the _Prussic_, that rises in distillation in combination with water.

ADULTERATIONS. Sulphuric acid, as it does not produce any turbid appearance in vinegar, is generally the acid selected for sharpening it; but it must be remembered, that the maker is allowed by law, to mix one thousandth of its weight of Sulphuric acid[327] with it; so that the _muriate of baryta_ when added to such vinegar may be expected to produce 1⅕ grain of insoluble _sulphate_ in every fluid-ounce; if a more considerable quantity of precipitate occurs, we may infer that an excessive proportion of sulphuric acid is present; although some allowance ought perhaps to be made for the presence of the sulphates of potass and lime, which are always contained in vinegar. Of this vinegar 1000 grains should saturate 148 grains of crystallized sub-carbonate of soda; a fluid-ounce of the same, 68–3/4 grains.[328] For the purpose of making the vinegar appear stronger, acrid vegetables, as _grains of Paradise_, _berries of Spurge Flax_, _Capsicum_, _Pellitory of Spain_, &c. are sometimes infused in it, but by tasting it with attention, the pungency of such substances may be easily detected. For the other adulterations, see _Acidum Aceticum_.

The purest vinegar which I have ever examined is that manufactured from malt, by Mr. Mackintosh of Glasgow. The strongest malt vinegar is termed _proof vinegar_, and is called by the manufacturer No. 24; it is estimated to contain 4·73 per cent. of real acetic acid.[329] Its strength in relation to the other forms of acetic acid, will be seen by referring to the MEDICINAL DYNAMETER, and to the table inserted under the article ACIDUM ACETICUM FORTIUS. In the former Editions of this work it was stated, that a Vinegar had of late years appeared in the market produced from the distillation of wood, (_Pyroligneous Acid_.) This article has now come into very general use; and the manufacturers have at length succeeded in divesting it of that empyreumatic flavour which had so long rendered it objectionable. See _Acidum Aceticum Fortius e Ligno destillatum_.

ACETUM COLCHICI. L. _Vinegar of Meadow Saffron._

Vinegar appears to be a solvent of the acrid and medicinal principle which resides in the bulb of this plant. DOSE fʒss to fʒij. in any bland fluid. See _Colchici Radix_.

ACETUM SCILLÆ. L.E.D. _Vinegar of Squill._

This preparation is an acetic solution of the acrid matter of the Squill, upon which its medicinal efficacy depends.[330] DOSE fʒss to fʒij. in cinnamon or mint water. See _Scillæ Radix_. FORM. 107, 114. Alkalies and their carbonates are chemically incompatible with these _Vinegars_. This preparation, as well as the _Oxymel_, deposites when long kept a precipitate consisting of _citrate of lime_ and _tannin_, but its medicinal efficacy is not on that account impaired.

ACIDUM ACETICUM DILUTUM. L. Acidum Acetosum Distillatum. E. Acetum
Distillatum. D.

_Common Distilled Vinegar._

QUALITIES. _Odour_, fainter and less agreeable than common vinegar (_Acetum_): _Taste_, less acid; _Colour_, none. SPECIFIC GRAVITY; Mr. Phillips states, that when prepared according to the directions of the Pharmacopœia, it varies from 1·007 to 1·009; and that 1000 grains of the latter require for their saturation, 145 grains of crystallized sub-carbonate of soda. I apprehend, however, that it will be found quite impossible to obtain a dilute acetic acid equal in strength or specific gravity, to that last mentioned, by the process of the London College;[331] it may even be doubted whether it can be produced of the specific gravity 1·007. The general run of distilled vinegar as found in the shop of the druggist, varies from 1·005 to 1·006, and contains from 2·80 to 2·826 per cent. of real acid; when of the specific gravity of 1·009 it would contain about 4·73 per cent. Dr. Powell states (_Translation of the Pharmacop: of London_, 1815) that “one fluid-ounce ought to dissolve at least thirteen grains of _white marble_;” or, what is equivalent to it, 39·67 grains of crystallized _Sub-carbonate of Soda_; acid of this strength corresponds very nearly with six degrees of the Revenue Acetometer, the proportions being as follow, 100 grains of Pharmacopœia strength will saturate 8·68 grains of crystallized _Sub-carbonate of Soda_; 100 grains of acid of 6° of the Acetometer will saturate 8·70 grains of the salt. CHEMICAL COMPOSITION. Acetic Acid more largely diluted than that in vinegar, with very minute portions of uncombined mucilage and extractive. SOLVENT POWERS. It is capable of dissolving all those vegetable principles which are soluble in water, and in some cases, as in _Squill_, _Colchicum_, and in several _Aromatics_ and _Narcotics_, its acid appears to extend its solvent powers; at the same time it often modifies or diminishes the medicinal virtues of the substances, as for instance those of _Narcotics_; this circumstance considerably limits its pharmaceutical application; when however it is employed, a portion of spirit should be always added, in order to counteract the spontaneous decomposition to which it is liable, and the acetic compound should be preserved in stopped bottles. Acetic acid does not dissolve true resins, but it has some action on gum resins. MEDICINAL USES. It is refrigerant, and may be advantageously administered in hemorrhage; especially in cases where the acetate of lead has been given, since the solubility of this latter substance is increased by it. See Form. 57; externally, it may be a convenient adjunct to lotions containing lead. _See Form. 147._ In consequence of its chemical action upon osseous matter, it has been much employed at the Gloucester Infirmary to hasten exfoliation of carious bone. ADULTERATIONS. _Sulphuric Acid_ may be detected by a precipitate being produced on the addition of acetate of baryta: this test however will not answer for its detection in common vinegar, for the reason stated under that article. See _Acetum_. _Sulphurous Acid_ may be recognised by drawing a little of the vapour into the lungs. The presence of _Nitric Acid_ may be discovered by saturating the suspected sample with pure potass, evaporating to dryness, and then treating the product with a highly concentrated alcohol, the acetate of potass will be thus dissolved, but as it exerts no action on the _Nitrate_ it will be found in the residuum, and may be recognised by its deflagration, when thrown upon burning charcoal;[332] _Copper_ may be detected by the acid assuming a blue colour, when supersaturated with ammonia; and _Lead_, by a solution of sulphuretted hydrogen, producing a dark coloured precipitate. _Tin_ however is the metal with which distilled vinegar is more usually contaminated, for no vegetable acid will act upon lead while any tin is present in the mixture, since the latter, being more oxidable than the former, is exclusively dissolved.

ACIDUM ACETICUM FORTIUS. L.

(_Acidum Aceticum._)
(_e Ligno Destillatum._)

_vulgo, Pyroligneous Acid._

The acetic acid from wood has been very generally introduced to supersede the use of distilled vinegar for the purposes of Medicine and the Arts.[333] It is at length found to be capable of such complete separation from all foreign matter as to afford a perfectly pure acetic acid, invariable in its acidifying power, and immutable in its chemical properties. In justice to the skill and industry of Messrs. Beaufoy and Co. of South Lambeth, I beg to state that I have examined various specimens of this acid from their manufactory, and that I find it free from those impurities which have hitherto constituted an insuperable objection to its introduction into the Materia Medica. The purified _Pyroligneous_ acid, manufactured by this company, and sold under the name of “_Improved Distilled Vinegar_,” is perfectly free from any unpleasant taste, as well as colour and sediment; and it forms a limpid and colourless solution with ammonia. The common distilled vinegar of the shops varies essentially in strength as well as purity, differing in acidifying power from 30 to 40 per cent. in value: it is sometimes 7 degrees, and at others less than 5, by the Revenue Acetometer;[334] and hence has arisen the difficulty of procuring an uniform article for medical application, a difficulty which the introduction of the _pyroligneous_ acid seems calculated to overcome, as it may be procured from the manufacturers of any degree of concentration,[335] from 6 degrees of the Acetometer, or 2·826 per cent. of real acetic acid to 130 degrees, or 61·49 per cent. of acid; and even of still higher strength if required; their common, or _Proof_ acid is about equivalent in strength to that of the best Malt Vinegar, of which 100 grains will saturate 14½ grains of crystallized _Sub-carbonate of Soda_, and consequently contains 4·73 per cent. of real acid, and will require at least one half part of water to reduce it to the strength of the best common distilled vinegar. It is found that acetic acid of 45 per cent. real acid, or of 95° of acetometer strength, dissolves Camphor and the Essential Oils very readily.

The “ACIDUM ACETICUM FORTIUS,” which is now introduced into the Materia Medica of the London College, is directed to have a specific gravity of 1·046.[336] It is exactly six times the strength of Proof vinegar, or the strong Malt vinegar manufactured, but it requires to be diluted with nine times its weight of water to reduce it to the strength of the ordinary samples of distilled vinegar. Mr. Phillips states, that he has not met with acetic acid of greater specific gravity than 1·043,[337] being five times the strength of vinegar of specific gravity 1·009.[338] The strongest acid that can be procured is the _Glacial_ acid, which exists in a crystallized state under 50° _Fah._ It contains 79 per cent. of real acid, and is consequently of the strength of 167·5 of the Acetometer. If this acid be kept perfectly still, it may be reduced several degrees below its crystallizing point in a fluid state, when the slightest agitation of the vessel instantly occasions it to solidify. It will greatly facilitate our inquiries into the strength of different samples of acetic acid to know, that the representative numbers of acetic acid and pure white marble coincide on the scale of equivalents; it therefore follows that the weight of marble dissolved by a hundred grains of any acetic acid, will at once represent the percentage of real acid in such a sample.

The Impure Pyroligneous acid, as it first comes over, contaminated with Tar, has, it is said, been very successfully employed as a lotion in Lepra, scrophulous ulcerations, chronic inflammation of the eyes, and edges of the eye-lids, and for promoting digestion of irritative ulcers, or those connected with carious bone. It has also been injected into sinuses to produce healthy discharge and adhesive inflammation.[339] M. Monge discovered that this acid has the property of preventing the decomposition of animal substances; it is sufficient to plunge meat for a few moments in this acid, even slightly empyreumatic, to preserve it as long as you please. “Putrefaction,” it is said, “not only stops but retrogrades.” To the empyreumatic oil a part of this effect has been ascribed, and hence has been explained the agency of wood smoke in the preservation of tongues, hams, herrings, &c.

ACIDUM ACETOSUM FORTE, E. Acidum Aceticum. D.

_Radical Vinegar._

The process for this preparation has not retained its place in the London Pharmacopœia, as it is now universally superseded by the Acetic acid distilled from wood. Since however it possesses peculiar chemical habitudes, it claims some notice in this work. The concentrated acid obtained from the decomposition of acetic salts, by the action of sulphuric acid, is pungent, acrid, and volatile, and when heated with free access of air, it takes fire very readily. Its solvent powers are much greater than those of distilled vinegar; it is capable of dissolving camphor, resins, and essential oils[340] copiously, but they are precipitated by dilution; it combines with alcohol, and forms a species of ether; with water it unites in any proportion, heat being evolved by the mixture. Gold, platinum, glass, and earthenware, can alone retain this acid without being corroded. It blisters the skin immediately.

I shall conclude this article by the introduction of a Table, which I have constructed with considerable care, for the use of the practical Chemist. The accuracy of the results may be depended upon, since it has been tested by several different modes of enquiry. The Medicinal Dynameter will give the equivalents in any other denomination that may be required.

A TABLE EXHIBITING THE ACETOMETER STRENGTHS, SPECIFIC GRAVITIES,
PERCENTAGE OF REAL ACID, EQUIVALENT VALUE, AND SATURATING POWER, OF THE
MORE IMPORTANT PREPARATIONS OF ACETIC ACID.

┌────────────────┬──────────┬────────┬──────────┬───────────┬─────────┐ │ ACIDS. │ │ │ │ │Grains of│ │ │ │ │ │ │ Sub- │ │ │ │ │ │ │carbonate│ │ │ │ │ │ │ of Soda │ │ │ │ │ │ │saturated│ │ │ │ │Percentage│ │ by 100 │ │ │Acetometer│Specific│ of real │Equivalents│grains of│ │ │strength. │Gravity.│ Acid. │in Minims. │ acid. │ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acetum │ │ │ │ │ │ │ Destillatum │ 5·9°│ 1·005│ 2·80│ 810│ 8·58│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │ D° │ 6°│ 1·006│ 2·826│ 803│ 8·66│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │ D° │ 7°│ 1·007│ 3·42│ 663│ 10·48│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │ D° │ 10°│ 1·009│ 4·73│ 480│ 14·5│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acetum (Proof) │ 10°│ 1·014│ 4·73│ 480│ 14·5│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acid Acetic: │ │ │ │ │ │ │ Fort. │ 50°│ 1·043│ 23·67│ 96│ 72·5│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acid Acet: Fort.│ │ │ │ │ │ │ P. L. │ 60°│ 1·048│ 28·43│ 80│ 87│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acid: Acet: │ │ │ │ │ │ │ Fort. │ 75°│ 1·059│ 35·475│ 64│ 108·75│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acid: Acetic, D.│ │ │ │ │ │ │ Acid: Acetos: │ │ │ │ │ │ │ Fort. E. │ 145°│ 1·070│ 68·5│ 33·1│ 210·25│ ├────────────────┼──────────┼────────┼──────────┼───────────┼─────────┤ │Acid: Acetic: │ │ │ │ │ │ │ Fort. │ │ │ │ │ │ │ (_Glacial._) │ 167.5°│ 1·063│ 79│ 28·6│ 242·875│ └────────────────┴──────────┴────────┴──────────┴───────────┴─────────┘

The reader will observe an anomaly with regard to the specific gravity of the acid of 145 of the acetometer, when compared with the _glacial_ acid. The fact is, that by diluting this latter preparation with a small portion of water we augment its specific gravity, a circumstance peculiar to this acid.

ACIDUM BENZOICUM. L.E.D.

_Benzoic Acid._ Vulgo, Flowers of Benzoin, or _Benjamin_.

QUALITIES. _Form_, small feathery crystals of a brilliant white colour, which are not brittle, but possess a kind of ductility and elasticity, and, on being rubbed in a mortar, assume the consistence of paste. _Odour._ As generally met with, it possesses a peculiar aromatic smell, but this depends upon the oily matter which adheres to it, for Mr. Guise informs us, that on dissolving the benzoic acid in as little alcohol as possible, filtering the solution, and precipitating by water, the acid will be obtained pure, and void of smell, the odorous oil remaining dissolved in the spirit. _Taste_, rather acrid and sour; _Specific Gravity_, ·667. It is not altered by exposure to air. SOLUBILITY. Four hundred parts of cold water dissolve but one, although the same quantity of boiling water dissolves twenty parts, nineteen of which separate on cooling; in alcohol it is soluble in a much greater proportion. MEDICINAL USES. It is said to be stimulant and expectorant; in certain cases of tracheal irritation, a pill, composed of two grains of Benzoic acid, and three of Extract of Poppy, has been found serviceable. OFFICINAL PREPARATIONS. _Tinctura Camphoræ Composita_, L.D. _Tinct: Opii Ammoniat:_ E. IMPURITIES. The crystals ought not to be discoloured; they should dissolve without residuum in alcohol, and when subjected to heat, ought to be entirely volatilized.

Although this acid is commonly procured from the resinous substance called Benzoin, yet it exists extensively in other vegetable, and in some animal substances. In the Tonca bean (_Dipterix odorata_) it is frequently to be seen beautifully crystallized on its surface. It exists also in vanello; cinnamon; cloves; ambergris; in the urine of children, and sometimes in that of adults, and always in that of quadrupeds living on grass and hay.

ACIDUM CITRICUM. (_Crystalli_) Citric Acid.

_Concrete Acid of Lemons._

QUALITIES. _Form_, crystals which are right rhombic prisms, white, semi-transparent, and persistent. _Taste_, extremely acid, almost caustic. SOLUBILITY, f℥j of cold water dissolves ʒx, but of boiling, ℥ij. ʒx of the crystals dissolved in a pint of water, are about equivalent to one pint of lemon juice, the solution however if kept is liable to spontaneous decomposition. The following table of equivalents may be found of practical use; the author is aware that they do not exactly agree with the proportions of Dr. Haygarth, but they are the results of careful and repeated experiments, and as such they are submitted with confidence.

EQUIVALENT PROPORTIONS OF CONCRETE CITRIC ACID AND LEMON JUICE,
NECESSARY FOR THE NEUTRALIZATION OF ALKALINE SALTS.

┌──────────────────────┬──────────────────────┬───────────────────────┐ │ Citric Acid. │ Lemon Juice. │A Scruple of Alkalies. │ ├──────────────────────┼──────────────────────┼───────────────────────┤ │ grs. x. │ fʒiij │ Carbonate of Potass. │ ├──────────────────────┼──────────────────────┼───────────────────────┤ │ grs. xv. │ fʒiiij │ Sub-Carbonate of │ │ │ │ Potass. │ ├──────────────────────┼──────────────────────┼───────────────────────┤ │ grs. xxv. │ fʒvij │ Sub-Carbonate of │ │ │ │ Ammonia. │ └──────────────────────┴──────────────────────┴───────────────────────┘

These alkaline citrates are decomposed by the _oxalic_, _tartaric_, and the stronger _mineral acids_, and by the solutions of _lime_ and _barytes_. _Form. 107, 123, 137, 168._

Citric acid decomposes the following salts, _viz._ _The Alkaline, Earthy, and Metallic Carbonates_; _the Alkaline and Metallic Acetates_; _the Sulphurets of Earths and Alkalies, and Alkaline Soaps_. It is also incompatible with _Tartrate of Potass_, which it converts into citrate and super-tartrate of potass. It curdles the milk of most animals, but it does not produce that effect on human milk, whether applied hot or cold. ADULTERATIONS. _Tartaric Acid_, with which it is sometimes mixed, may be detected by adding to the solution an excess _of Potass_, which will instantly form with it an insoluble super-tartrate, and precipitate in granular crystals, or, if a little of the suspected acid be saturated with potass, and then boiled with a dilute solution of muriate of Platinum, if tartaric acid be present, a black protoxide of Platinum will be precipitated. If we add the tartrate of potass for this purpose, we may be deceived, for the citric acid, by neutralizing a portion of its base, will convert the remainder into super-tartrate. See _Potassæ Tartras_. _Sulphuric Acid_ is known by the acetate of lead producing a precipitate, insoluble in nitric acid. _Muriatic Acid_ may be discovered in the same manner, substituting only an acidulous solution of nitrate of silver for the acetate of lead. The presence of _Oxalic Acid_ may be inferred, if the solution, when added to that of sulphate of lime, produce a precipitate. Malic acid has the power of precipitating silver, mercury, and lead, from their solutions in nitric acid, but no doubt or difficulty can arise from this circumstance, for the fact of its forming a soluble salt with lime will prevent every chance of accidental intrusion, and its price at once secures us against its fraudulent introduction; it might moreover be easily detected by throwing the suspected precipitate upon burning coals, when it would be decomposed. Where the presence of _lime_ is suspected, it may be known by dissolving some of the crystals in water, saturating the solution with ammonia, and then treating it with the oxalate of that alkali, which, if lime be present, will immediately separate it in a palpable form. The juices of many other fruits besides the lemon and lime, will furnish the citric acid in abundance, and may be obtained from them by a similar process; e. g. VACCINIUM OXYCOCCUS, the _Cranberry_; PRUNUS PADUS, the _Bird’s Cherry_; DULCAMARA SOLANUM, the berry of the _Nightshade_; CYNOSBATUS, vel ROSA CANINA, the hep or fruit of the _Wild Briar_. There are many plants whose juices contain combinations of the _Citric_ and _Malic_ acids in considerable abundance, such as FRAGARIA VESCA, the _Wood Strawberry_, and the common _Raspberry_; RIBES RUBRUM the _Red Gooseberry_; VACCINIUM MYRTILLUS, the _Bilberry_; CRATÆGUS ARIA, the _Hawthorn_; PRUNUS CERASUS, the _Black Cherry_, &c. This fact is interesting, since the juices of such fruits have been long known to possess the property of dissolving the _tartareous_ incrustations on the teeth.

ACIDUM HYDRO-CYANICUM.

_Hydro-cyanic Acid._ _Prussic Acid._

This peculiar acid exists in a great variety of native combinations in the vegetable kingdom,[341] and imparts to them certain properties which have been long known, and esteemed in medicine. It is, however, only lately, that it has been administered in its simple but diluted form. As few practitioners will choose to prepare the acid, it seems unnecessary in the present work to dwell upon the merits of the different processes which have been proposed for its preparation; for a full account of them, as well as for other details of importance, the practitioner is advised to consult a work by Dr. Granville, entitled “_An Historical and Practical Treatise on the use of Prussic Acid. Second Edition. London, 1820._”

QUALITIES. A colourless transparent liquid, although it occasionally exhibits a yellow tinge; _Odour_ like that of bitter almonds; _Taste_ bitterish and peculiar: these properties however are soon lost by exposure to air and light, and the acid undergoes spontaneous decomposition. CHEMICAL COMPOSITION. The true nature of _Prussic_ acid was not ascertained until 1815, when Gay Lussac presented to the Royal Institute of France, a memoir which at once developed its real chemical constitution; and it is now admitted to consist of a peculiar gaseous and highly inflammable compound of carbon and nitrogen, to which the name _Cyanogene_ has been assigned, and of hydrogen; the latter body acting as the acidifying principle, whence the term _Hydro-cyanic_ acid is well contrived to express its composition. The medicinal, or _diluted_ acid, however, contains but a small proportion of this concentrated compound; according to M. Majendie, one part of the acid of Gay Lussac and eight parts and a half of water, by weight, or one part of acid with six times its volume of water, constitute the preparation which should be used in medicine; and which, to avoid the possibility of mistake, ought always to be prescribed as the Acidum Hydro-cyanicum _dilutum_, and is, in fact, the _Prussic acid_ of Scheele. Dr. Ure, who has lately taken considerable pains upon this subject, has constructed a table exhibiting the relations between the specific gravities, and quantities of real acid, in preparations of different strength; from these experiments it would appear that an acid of specific gravity 0·996 or 0·997 is such as is usually prescribed in medicine.[342] MEDICAL USES. In a sufficient dose, hydro-cyanic acid instantly destroys life by extinguishing the nervous energy of the body;[343] but it has at the same time been observed that animals submitted to its action would often continue to breathe for several hours freely, and to circulate their blood, although no trace of sensibility or muscular contractility could be found after its application. This remarkable property of extinguishing the general sensibility, without any ostensible injury to respiration and circulation, naturally led to a belief that the hydro-cyanic acid, or prussic acid, might be advantageously used in cases of excessive sensibility and irritation, particularly when these two morbid states are likely to affect either the respiratory organs or the circulation generally. This kind of analogical reasoning, it is said, induced Professor Brera, ten years ago, to administer it in cases of high pulmonary and other inflammations, in doses of four drops twice a day; when, as we are told, the violence of the disease was quickly subdued. The remedy, however, does not appear to have excited much attention, until after the first essay of Dr. Majendie, who deserves whatever credit may belong to its introduction. Seven years of trial have elapsed, and the general sense of the medical profession with respect to its utility may now be collected. As a palliative in certain spasmodic coughs, there is reason for supposing that it _may sometimes_ be useful, but in that species of pulmonary irritation for which it was at first so greatly extolled, I will venture to assert that it is far inferior in efficacy to well directed doses of _Conium_. But there is another class of diseases in which its exhibition is said to prove useful, in dyspeptic affections attended with heartburn; where it is supposed to be capable of reducing the morbid irritability of the stomach, and thereby of enabling the juices of that organ to be more slowly secreted and of a more healthy character. Dr. Elliotson has published the result of his treatment of stomach complaints with this medicinal agent, and would appear to appropriate to himself the merit of originating the practice, a claim which Mr. Thomson, in the third edition of his Dispensatory, refuses to concede.[344] As a local remedy, prussic acid has also received no small share of commendation, and it has been said that it is the only application that can be depended upon for allaying the cutaneous irritation so frequently attendant upon certain impetiginous affections. It must, however, be confessed that this medicine is rapidly declining in popularity.[345] Any prejudice raised against it, upon the ground of its poisonous activity in large doses, is too absurd to be believed; the knife and the caustic are unquestionably powerful, and may therefore become dangerous instruments; but who ever blames the surgeon for employing a sharp knife or an active caustic, seeing that both are to be directed by his eye, and guided by his hand? FORMS OF EXHIBITION. It may be conveniently administered in any liquid vehicle, as distilled water, camphor mixture, or in some vegetable infusion. See _Supplementary Formulæ_, 1, 2, 3. A question has lately arisen whether the effects of the prussic acid might not be more conveniently ensured by the administration of some vegetable[346] in which it exists as a native ingredient; a company of associated Physicians, Surgeons, and Naturalists at Florence, have accordingly expressed their joint opinion, that the essential oil of the _Prunus Lauro Cerasus_ is to be preferred in medical practice to all other preparations which contain the hydro-cyanic acid; for, say they, unlike the distilled water of the plant, and pure prussic acid, it contains the same proportion of active matter, and of the same power, whether recently prepared or not; whether made in one place or another; or whether it has been exposed or not to the air, light, or heat. They are also of opinion that olive oil forms the best vehicle for its exhibition in the proportion of one ounce to twelve drops of the essential oil. Other practitioners again prefer _Laurel Water_, made by distilling two drachms of the fresh leaves chopped, with four ounces of water, recommitting the distilled water twice afterwards on the same quantity of fresh leaves, and making ultimately four ounces of the menstruum, of which from ♏︎xxx to fʒj every six hours may be given until a sedative effect is produced. See _Oleum Amygdalæ Amaræ_. INCOMPATIBLE SUBSTANCES. Hydro-cyanic acid is decomposed by most of the _oxydes_ usually employed in medicine, particularly by those of _Mercury_ and _Antimony_. The alkalies do not appear to diminish its efficacy. _Nitrate of Silver_, and the salts of iron occasion precipitates; nor ought the _sulphurets_, the _mineral acids_, or _chlorine_ to enter with it into prescriptions. DOSE. Of the medicinal, or _diluted_ hydro-cyanic acid, ♏︎ij,–viij. There is however considerable difficulty with regard to the strength of the dilute acid employed in medicine, since the density is a criterion of greater nicety than can be conveniently used by the majority of practitioners; in fact, as Dr. Ure has observed, the liquid at 0·996, contains about double the quantity of real acid, which it does at 0·998. Dr. Ure has accordingly proposed another test of the strength of this powerful and dangerous medicine, which is not only easier in use, but more delicate in its indications;[347] it is as follows. To 100 grains, or any other convenient quantity of the prussic acid, contained in a small phial, add in succession, small quantities of the peroxide of mercury, (the common _red precipitate_ of the shops) in fine powder, till it ceases to be dissolved on agitation. The weight of the red precipitate taken up, being divided by four, gives a quotient representing the quantity of real prussic acid present. By weighing out before hand, on a piece of paper, or a watch glass, forty or fifty grains of the peroxide, the residual weight of it shews at once the quantity expended. The operation may always be completed in five minutes, for the red precipitate dissolves as rapidly in the dilute prussic acid, with the aid of slight agitation, as sugar dissolves in water. ADULTERATIONS. If, says Dr. Ure, the presence of muriatic acid be suspected, then the specific gravity of the liquid compared with the gravity of the peroxide dissolved, will shew how far the suspicion is well founded; thus if 100 grains of acid, specific gravity 0·996, dissolve more than 12 grains of the red precipitate, we may be sure that the liquid has been contaminated with muriatic acid. _Nitrate of Silver_, in common cases, so valuable a reagent for muriatic acid, is unfortunately of little use here, for it gives with prussic acid, a flocculent white precipitate, soluble in water of ammonia, and insoluble in nitric acid, which may easily be mistaken by common observers, for the _chloride_ of that metal. But the difference in the volatility of prussiate and muriate of ammonia may be had recourse to with advantage; the former exhaling at a very gentle heat, the latter requiring a subliming temperature of about 300° _Fah._ After adding ammonia in slight excess to the prussic acid, if we evaporate to dryness at a heat of 212°, we may infer from the residuary sal ammoniac, the quantity of muriatic acid present.