Chapter II: BLEACHING of =Linen=:--Linen may be bleached in a similar way to (30)

=Eau des Fées--Fairy Water.= A hair wash. A solution of 1-1/4 parts lead sulphite in about 3 parts sodium hyposulphite, 7-3/4 parts glycerin, and 88 parts water. According to the directions for use, more than three bottles of 120 grammes of the Fairy Water should not be used before the hair has been treated with Eau de Poppée, and, to raise it to the highest possible degree of beauty, with Huile régénératrice d'Hygie. (Hager.)

=Eau de Hebe.= For freckles. To be applied with a small sponge in the evening and washed off in the morning. Lemons, cut small, digested in a closed flask with distilled vinegar, lavender vinegar, oil of lemon, and rosemary, and filtered.

=Eau de Java Anticholerique= is a solution of camphor and carbolic acid in spirit. (Casselmann.)

=Eau de la Floride.= A colourless fluid with a greenish-yellow deposit consisting of sugar of lead, 50 parts; flowers of sulphur, 20 parts; distilled water, 1000 parts. (F. Eymael.)

=Eau de Lechelle= may be replaced by a filtered mixture of 200 parts aqua aromatica, 300 parts aqua dest., 10 parts acid. carbol., 10 parts ol. thymi, 20 parts acid. tannic.

=Eau de lys de Lohse= (Lohse formerly--before the French war--Lohsé, Berlin). A cosmetic consisting of 2 grammes zinc oxide, 2 grammes prepared talc, 4 grammes glycerin, and 200 grammes rose water. (Schädler.)

=Eau de Mont Blanc.= A hair dye. A solution of nitrate of silver.

=Eau de Naples.= Neapolitan washing solution. A mixture of 12 parts borax, 100 parts distilled water, 50 parts rose water, 1 part camphor, 4 parts tinct. benzoin. (W. Hildwein.)

=Eau de Quinine--Glycerin Hair Wash, with Extract of Peruvian Bark= (A. Heinrich, Leipzig). For removing scurf and strengthening the hair. 2 grammes balsam of Peru, 6 grammes castor oil, 60 grammes rum, 35 grammes water, 5 grammes tincture of red cinchona. (Hager.)

=Eau de Vienne.= A hair dye from Paris. Two fluids, one of which is a solution of nitrate of silver in ammoniacal water, and the other a solution of pyrogallic acid.

=Eau Dentifrice de Mallard.= Star anise, common anise, cinnamon, cloves, of each, 8 parts; guaicum wood, 10 parts; brown cinchona, 6 parts; rose leaves, 5 parts; nutmegs, 2 parts, are placed in a displacement apparatus and percolated with 3 parts cochineal; 12-15 parts water, 1000 parts sp. vini; sp. gr. ·860. The tincture is displaced with water and 1000 parts are mixed with 7 parts of a mixture of peppermint oil, spirit of scurvy grass, and tinct. of benzoin, allowed to stand and filtered.

=Eau Dentifrice des Cordillères.= An Indian recipe. 360 parts strong spirits, 330 parts water, 2-1/2 parts extract of red or yellow cinchona, 1 part oil of cinnamon, 2 parts oil of cloves, 3 parts oil of anise, 5 parts oil of peppermint. (Hager.)

=Eau Ecarlate--Scarlet Water.= (Bürdel). For renovating red linen and woollen fabrics. Oxalium, 25 parts; soda, 16 parts; potash, 5 parts; water, coloured with cochineal and slightly perfumed, 1000 parts. (Sauerwein.)

=Eau Lajeune.= A hair dye. An elegant pasteboard box, in which are three bottles of fluid and two bone-handled tooth-brushes. No. 1 contains a clear fluid consisting of pyrogallic acid 1·5 gramme, ·3 gramme colouring matter of alkanet, 17·5 grammes spirit of wine, 27 grammes water. No. 2 is filled with a thick brown fluid, which from decomposition has produced a deposit sometimes brown, sometimes grey. This partly-decomposed fluid was originally a mixture of silver nitrate, 3·5 grammes; ammonia, 4·5 grammes; gum arabic or some similar mucilage, 2·5 grammes; distilled water, 23 grammes. No. 3, labelled "Fixateur," contains 7·5 grammes fluid, consisting of ·5 gramme sodium sulphide, 7 grammes distilled water. The directions for use, translated into various languages, say--Dissolve 10 grammes subcarbonate of soda in half a litre of warm or cold rain water, and with this wash the grease from the hair. Afterwards rinse it in clear water, and dry it thoroughly with a cloth. Pour one part of fluid No. 1 into a saucer, and with brush No. 1 apply it to the roots of the hair. Allow it two or three minutes to dry, then rub the hair with an old linen cloth to remove the superfluous moisture. Next repeat the operation, using fluid and brush No. 2, and without waiting wash the hair with warm or cold soapy water. This hair dye is quite harmless, and leaves no marks on the skin behind it. _To use it for the Beard._--The process is the same as that for the hair, except that instead of the soda solution, ordinary soap is to be used to cleanse the beard from grease. It often happens that when the user of the dye has not taken ordinary care in cleansing the hair, the latter becomes of a false and unnatural tint. In this case the Fixateur should be used. A small sponge should be moistened with this and passed over the hair, which will make the colour natural and glossy. The Fixateur as well as the sponge must only be used in this way. It may be employed two days after the first operation without it being necessary to dye the hair anew. (Hager.)

=Eau Medicinales= are either simply watery solutions (HYDROLÉS, HYDROLATURES, SOLUTIONS PAR L'EAU), or distilled water (EAUX DISTILLÉES); or they are vinous or alcoholic tinctures or solutions of essential oils, aromatics, or more active drugs. See CORDIALS, HAIR DYES, PERFUMERY, SPIRITS, TINCTURES, WATERS, &c.

=Eau Tonique de Chalmin= is a perfumed solution of tannin.

=Eau Tonique Parachûte des Cheveux.= To prevent the falling off of the hair. Macerate some pieces of violet root for some days in 120 grammes rose water, filter, and add to the fluid 2 decigrammes sulphate of iron, 3 drops vinegar, 1·3 gramme each of tincture of benzoin and balsam of Peru, 7·5 grammes Provence oil, and 10 drops oil of bergamot. (Dr Casselmann.)

=Eau Virginale= (Chable). Lead acetate, zinc sulphate, of each 1 part; distilled water, 28 parts; eau de Cologne, 12 parts. Dissolve and mix; allow to stand for a month and filter. A spoonful mixed with a glass of water to be used as a vaginal injection. (Reveil.)

=Eaux=, in perfumery, are solutions of the fragrant essential oils in spirit, as eau de Cologne, eau de bouquet, &c.; or they are distilled waters, largely charged with the odorous principles of plants, as eau de rose, eau de fleurs d'oranges, &c.

=Eaux=, of the liqueuriste, are aromatised spirits or cordials.

=EB'LANINE.= The yellowish-red, crystallisable, solid substance, which is left behind in the retort, when wood spirit is rectified from quicklime. It is insoluble in water, and sublimes without fusion at 273° Fahr.

=EBONITE.= The only difference between this and vulcanite, consists in the colouring materials used. See CAOUTCHOUC.

=EB'ONY.= The wood of the _Diospyrus Melanoxylon_, an East Indian tree, of the natural order _Ebenaceæ_. Two other species of the same genus, namely, _Diospyrus Ebenus_ and _D. Ebenaster_, yields respectively MAURITIUS EBONY and the BASTARD EBONY of Ceylon. Pale-coloured woods are stained in imitation of ebony (FACTITIOUS EBONY), by washing them with or steeping them in a strong decoction of logwood or of galls, and, when dry, washing them over with a solution of sulphate or acetate of iron. They are then rinsed in clean water, and the process is repeated, if required. The wood is lastly polished or varnished.

=EBRI'ETY.= See INTOXICATION.

=EBULLI''TION.= The state of boiling, or the agitation of a liquid arising from its rapid conversion into vapour by heat. Ebullition occurs in different liquids at very different temperatures, such temperatures being called their 'boiling-points.' Under the same circumstances the boiling-points are constant, and by observing them the chemist is often able to distinguish liquids which much resemble each other. The boiling-point of the same liquid may, however, vary considerably under different circumstances. The causes which induce variation are increased or diminished atmospheric pressure, the greater or less depth of the liquid, and the character of the containing vessel. Thus boiling water is colder by some degrees when the barometer is low, in bad weather, or at the top of a hill, than when the barometer is higher, in fine weather, or at the bottom of a valley or mine. There is a very simple and beautiful experiment, illustrative of the effect of diminished pressure in lowering the boiling-point of a liquid. A little water is made to boil for a few minutes in a flask or retort placed over a lamp, until the air has been expelled, and the steam issues freely from the neck. A tightly fitting cork is then inserted, and the lamp at the same moment withdrawn. When the ebullition ceases, it may be renewed at pleasure for a considerable time by the affusion of cold water, which, by condensing the vapour within, occasions a partial vacuum. Liquids in general boil from 60° to 140° lower than their ordinary boiling-points when heated _in vacuo_.

The following table furnishes very exact information respecting the effect of increasing pressure upon the boiling-point of water:--

Boiling water contained in a deep vessel is hotter than that in a shallow one, on account of the greater resistance in the one case than the other to the escape of the steam. It is also found that fluids boil at a lower temperature and more quietly in vessels with rough and spicular surfaces, than in those with smooth or polished ones. The boiling-point of water, as marked on the scale of the thermometer, is 212° Fahr., but in glass vessels, under common circumstances, it varies from

TABLE I.--_Boiling-points of Water at different
Pressures._ By Mr C. GREVILLE WILLIAMS.

--------------+-----------+---------------+-----------
Boiling-point | Barometer | Boiling-point | Barometer
° Fahr. | Inches. | ° Fahr. | Inches.
--------------+-----------|---------------+-----------
184 | 16·676 | 200 | 23·454
185 | 17·047 | 201 | 23·937
186 | 17·421 | 202 | 24·441
187 | 17·803 | 203 | 25·014
188 | 18·196 | 204 | 25·468
189 | 18·593 | 205 | 25·992
190 | 18·992 | 206 | 26·529
191 | 19·407 | 207 | 27·068
192 | 19·822 | 208 | 27·614
193 | 20·254 | 209 | 28·183
194 | 20·687 | 210 | 28·744
195 | 21·124 | 211 | 29·331
196 | 21·576 | 212 | 29·922
197 | 22·030 | 213 | 30·516
198 | 22·498 | 214 | 31·120
199 | 22·965 | 215 | 31·730
--------------+-----------+---------------+-----------

212·254° to 215·6°; whilst in perfectly pure and smooth glass vessels water may be heated to 221° Fahr. without boiling. That the elevation of the boiling-point in this case is due to the nature of the surface, may be at once demonstrated by throwing into water, about to boil in a glass matrass, a little iron filings or coarsely powdered glass, when ebullition will commence with almost explosive violence, at the same time that the temperature of the fluid will sink about 2° Fahr.

The boiling-point of water contained in ordinary vessels may be raised considerably above 212° Fahr., by the addition of saline matter, as will be seen in the following table, extracted from Mr C. G. Williams's excellent 'Handbook of Chemical Manipulation,'--

TABLE II.--_Boiling-points of Saturated Solutions of
various Salts at the ordinary Atmospheric Pressure._ By
C. G. WILLIAMS.

Name of Salt. Boiling-point.

Chloride of calcium 355° Fahr.
Acetate of soda 256 "
Nitrate of soda 246 "
Sal-ammoniac 236 "
Common salt 224 "
Cream of tartar 214 "

The above solutions are suitable for chemical baths. With the exception of the first, they furnish in their boiling-points temperatures, as nearly as can be obtained, 10° above each other. They were chosen by Mr Williams because, in 'fractionating' volatile substances, it is usual to separate the distilled products by differences of temperature equal to 10° Fahr. In long operations it is found inconvenient to employ a saturated saline solution for a bath (by which the highest temperature would be obtained), as the constant evaporation of the water induces the crystallisation of the salt. It is hence usual to keep it considerably below that point.

The following table, compiled chiefly from the pages of Dr Miller's 'Elements of Chemistry,' gives the boiling-points of several interesting substances.

TABLE III.--_Boiling-points of various Liquids at the
ordinary Atmospheric Pressure._

Name of Substance. Boiling-point.

Liquid carbonic acid -108° Fahr.
Liquid sulphurous acid + 17·6 "
Chloric ether 51·9 "
Aldehyd 69·4 "
Ether 94·8 "
Bisulphide of carbon 118·5 "
Bromide 145·4 "
Wood spirit 149·9 "
Alcohol (sp. gr. ·815) 173·1 "
Benzol 176·8 "
Dutch liquid 184·7 "
Acetic acid 243·1 "
Sulphur (melted) 609· "
Mercury 662· "

=EBUL'LIOSCOPE.= _Syn._ EBULLITION ALCOHOLOMETER, THERMO-ALCOHOLOMETER. "This instrument is essentially a thermometer, and its application to alcoholometry is based upon the fact that the boiling-point of a spiritous liquid is scarcely altered by the presence, within certain limits, of the substances which may be dissolved in it, and which, by increasing its specific gravity, render the ordinary alcoholometers or hydrometers useless for the purpose of indicating its alcoholic richness. The ebullioscope was invented by the Abbé Brossard-Vidal, of Toulon, and in its original form consisted of a spirit-lamp surmounted by a small boiler, into which a large cylindrical glass bulb was plunged, having an upright stem of such calibre that the quicksilver contained in them, by its expansion and ascent when heated, raised before it a little glass float in the stem, which was connected by a thread with a similar glass bead, hanging in the air. This thread passed round a pulley, which, turning with the motion of the beads, caused an index to move along a graduated circular scale, which represented on its face the per-centage of absolute alcohol in spirituous liquors of different boiling-points. This form of the apparatus being found inconvenient and liable to get disarranged, various improvements were made in it by MM. Conaty, Lerebour, and others. The modification of the instrument now in use, and known as Field's PATENT ALCOHOLOMETER, was made by the late Dr Ure, and can scarcely be improved on. It consists of a thermometer having a very minute bore and a large bulb, similar to that employed to determine the height of mountains from the boiling-point of water, but instead of thermometric degrees being marked upon the scale the per-centage under proof is placed on the left-hand side of the stem, and the per-centage content of proof spirit on the right-hand side. These commence at 178·5° Fahr., the temperature at which 'proof spirit' boils, and which here forms the bottom of the scale. The succeeding number are based upon the boiling-points of mixtures of alcohol and water. The little boiler being charged, and about a teaspoonful of salt (35 gr.) being added, to prevent loss of alcohol by evaporation, the thermometer is set in its place, and the spirit-lamp lighted. When the mercury begins to rise out of the bulb of the thermometer, the 'damper-plate' is pushed in a little way, to moderate the heat. The eye is now kept steadily on the instrument, and as soon as the liquor boils freely, and the mercury becomes stationary in the stem, the indication is carefully noted, and the damper-plate pushed home to extinguish the flame.

"The ebullioscope is adjusted to the mean boiling-point of water under an atmospheric pressure of 29·5 inches. When the pressure is either higher or lower, both water and alcohol boil at a somewhat different temperature, to meet which a barometrical equation is attached to the thermometer by means of a small subsidiary scale. It is therefore necessary, prior to commencing the operation of testing any liquor, to charge the little boiler with pure water only, and to fix the thermometer in its place. When the water boils freely, the mercury becomes stationary in the stem, exactly opposite the true barometrical indication at the time. Should this be against the line 29·5, no correction will be required; but should it stand at any other line, above or below, then the various boiling-points will bear reference to that boiling-point only. In the latter case, the boiling-point of the water on the barometrical indicator must be set against the boiling-point of the liquid on the scale, when opposite the line--29·5 will be found the true strength. Thus:--the barometer being at 30 inches, and the indication or boiling-point being 72 u. p., 30 on the indicator must be placed against 72 u. p. on the thermometer, when against the line of 29·5 will be seen 69·6 u. p., the real strength of the sample tested.

"When a spirit is stronger than the 'excise proof,' its boiling-point varies too little with its alterations of strength to render the ebullioscope of much practical value. To make it applicable to the stronger spirits, it is therefore necessary to dilute them with exactly their own bulk of pure water before testing them, and then to double the resulting indication, as suggested by Dr Ure. Our own plan is always to do this when the spirit is stronger than 20 u. p.

"By means of the ebullioscope the alcoholic content of beer, wines, and spirits, of every variety and class, may be readily determined with sufficient accuracy for all practical purposes; and by methods which we shall hereafter point out, the amount of saccharine extractive, or sugar, in cordialised spirit, malt liquors and wines, may also be ascertained.

"The ebullioscope (Field's ALCOHOLOMETER) employed by us in numerous and extensive investigations connected with public hygiène, was made by Mr Long, of Little Tower Street, and is an instrument which should be in the hands of every wine and spirit merchant and licensed victualler, as well as every private gentleman who feels interested in the quality of the liquors in his cellar. The instrument is accompanied by a useful little pamphlet of directions and tables, which has been very accurately got up, as we understand, by the late Dr Ure, expressly for Mr Long." (A. J. Cooley.)

=ECHINOCOCCUS HOMINIS.= This creature, which is the larva of the _Tinæa Echinococcus_, is a very common parasite infesting man, and has been found in the human lungs, heart, kidneys, liver, spleen, ovaries, breasts, membrane of the throat, and the bones. The disease to which it gives rise is of a very long and painful nature, frequently terminating fatally, and one in which no remedies have hitherto been found of any avail. The part of the human economy most frequently attacked by the ravages of the Echinococcus is the liver, in the substance of which it gives rise to the formation of a hydatid tumour. This tumour is composed of a thick-walled cyst or bag, within which is another of a much more delicate texture. "This latter membrane is the mother-sac of the Echinococcus embryo" (Huxley), and corresponds with the germinal membrane of Professor Goodsir. It is studded with innumerable transparent cells, varying as extremes of measurement from 1/10000th to 1/3000th of an inch. It is the seat of development of innumerable Echinococci, and to this membrane, in a fresh hydatid tumour, they are found connected by a delicate membrane, either singly, or more commonly in clusters, the number of individuals on the cluster varying from 10 to 100 or more, as shown in the annexed woodcut."[271]

[Footnote 271: Aitken.]

The size of the embryo varies from 1/18th to 1/20th of a line to 1/10th to 1/18th, according as it is elongated or contracted. Fig. 2 represents two Echinococci. In the one the head is drawn within the vehicle, and in the other it is extruded.

Fig. 3 represents a transverse view of an echinococcus; S S are suctorial discs; the hooklets may be seen encircling a membranous disk.

In Fig. 4 we have a representation of the circlet of these hooklets, B, which are thirty-four in number; C gives various views of separate hooklets; _b_ is the base; _c_ the central extremity; _e_ the hooklets viewed upon their concave or inferior border. The dotted lines connecting _f_, _g_, _k_, represent the outer surface of the neck, and runs through the fixed point of the three hooks which move upon the central fixed process, as on the pivot.

The inhabitants of Iceland are said to suffer severely from the effects of the Echinococcus Humanus; it has been computed that a sixth of the population of the island are attacked by it.

=ECLECTIC REMEDIES.= These are medicines chiefly employed by a sect of American practitioners, self-styled "Eclectics." The medicinal properties appended to each of these preparations are those ascribed to them by the Eclectics themselves.

APOCYNIN. From the roots of _Apocynum_ and _Ros[oe]mifolium_. Given in jaundice, hepatic torpor, and constipation.--_Dose_, 1/2 to 2 gr.

ASCLEPEDIN. From _Asclepias tuberosa_. Expectorant, diaphoretic, and tonic.--_Dose_, 1 to 5 grains three times a day.

BAPTISTIN. From Wild Indigo. Given in liver affections.--_Dose_, 1/4 to 1/2 grain.

BAROSMIN. From _Buchu_. Diuretic, alterative, antispasmodic.--_Dose_, 2 to 4 grains.

CAULOPHYLLIN. From _Caulophyllum thalictroides_. Tonic and alterative, acts on the uterus.--_Dose_, 1/4 to 1 grain three times a day; as a parturient, 2 to 4 grains.

CERASEIN. From the _Cerasus virginiana_. Given as a substitute for quinine when this latter is inadmissible.--_Dose_, 5 to 10 gr.

CIMICIFUGIN. _Syn._ MACROTIN. From Black Snakeroot. Tonic, alterative, nervine, antiperiodic, and in chorea.--_Dose_, 1 to 6 gr.

CORNINE. From _Cornus Florida_ (Dogwood). Antiperiodic.--_Dose_, 10 grains.

EUPATORINE. From _Eupatoreum purpureum_. Diuretic.--_Dose_, 3 to 5 grains.

EUPHORBIN. From _Euphorbia corollata_. Emetic, cathartic, expectorant, and vermifuge.--_Dose_, 1 grain or less.

GELSEMIN. From _Gelsemium sempervirens_. Given in pneumonia, hysteria, and dysmenorrh[oe]a.--_Dose_, 1/4 to 2 grains. This must not be confounded with the powerful alkaloid, Gelsimia.

GERANIN, or GERANIIN. From _Geranium maculatum_. Astringent.--_Dose_, 1 to 5 gr.

HAMAMELIN. From _Hamamelis Virginica_ (Witch hazel). Astringent.--_Dose_, 5 grains.

HYDRASTIN. From _Hydrastis Canadensis_. Tonic.--_Dose_, 3 to 5 grains. This must not be confounded with the alkaloid Hydrasta.

IRIDIN. From the _Blue flag_. Alterative, sialagogue, anthelmintic.--_Dose_, 1/2 to 5 gr.

INGLANDIN. From _Butter-nut_. Given in chronic hepatic disorders and constipation.--_Dose_, 2 to 4 gr.

LEPTANDRIN. From _Leptandra Virginica_. Given in liver affections, chronic dysentery, diarrh[oe]a, and typhus.--_Dose_, 2 to 4 gr.

LYCOPIN. From _Lycopus Virginicus_. Given in hæmorrhage, diabetes, and dysentery.--_Dose_, 2 to 3 grains.

MYRICIN. From _Myrica cerifera_. Stimulant, astringent, and antispasmodic.--_Dose_, 2 to 10 grains.

POPULIN. From _Populus tremuloides_. Tonic and febrifuge.--_Dose_, 4 to 8 grains.

PRUNIN. From _Wild Cherry Bark_. Stimulant, tonic, and expectorant.--_Dose_, 1 to 2 gr.

RUMIN. From _Rumex crispus_. Action like rhubarb.--_Dose_, 3 grains.

SANGUINARIN. From _Sanguinaria Canadensis_. Hepatic and alterative.--_Dose_, 1/2 to 2 grains.

STILLINGIN. From _Stylingia sylvatica_. Given in bronchitis and laryngitis. Used externally as a stimulant. Internally, 1 drop with mucilage.

=EDELENZIANWURZELSAFT--Noble Gentian-root Juice--Enzian Extract--Extract of Gentian.= A water-clear, colourless Schnapps, which contains much fusel oil and has had some of the spirit removed, distilled from gentian plant. (Hager.)

=EDIBLE EARTHS.= There seems little reason to doubt that the inhabitants of many countries, especially during famine and in times of scarcity, use certain kinds of earth as food. In Spain, a particular kind of earth known as _bucaro_ is eaten; the Russian peasant partakes of his _rock-flour_; the Thuringian of his _rock-butter_; the Swede, of his _bergmehl_ or _mountain meal_; the native of Java of an earth known as _teneampa_; the Hindoo, of the so-called _Patna earth_; and the Persian of a species of soil known as _Gheli Giveh_.

Mr Molvar has analysed an earth, eaten by the poorer classes of the Neograd district in Hungary, and finds it has the following composition:--

Carbonic acid 40·357
Lime 51·488
Magnesia 0·110
Volatile matter 5·545
Ferrous oxide 0·158
Alumina 2·272

As the volatile matter seemed to be the probable means of nourishment, it was subjected to a special examination, and was found to contain, besides empyreumatic substances, 0·067 water, and 0·010 nitrogen.

Dr Schmidt, a German chemist, gives the following as the composition of 100 parts of the air-dried powder from the coast of the White Sea:--

Water given off at 100° C 0·260
Given off at a low red heat 0·835
Alumina 40·797
Ferric oxide 0·310
Magnesia 0·618
Lime traces
Soda 1·829
Potassa 9·845
Silicic acid, trace of fluorine, and loss 45·506

This earth is eaten by the Laplanders, who mix it with the flour of which they make their bread.

The Persian edible earth called _Gheli Giveh_ contains:--

+----------------------+------+
|Magnesic carbonate |66·963|
+----------------------+------+
|Calcic carbonate |23·634|
+----------------------+------+
|Sodium chloride | 3·542|
+----------------------+------+
|Sodic sulphate | 0·293|
+----------------------+------+
|Sodic carbonate | 0·598|
+----------------------+------+
|Magnesic hydrate | 1·311|
+----------------------+------+
|Ferric oxide | 0·092|
+----------------------+------+
|Alumina | 0·227|
+----------------------+------+
|Silicic acid | 0·765|
+----------------------+------+
|Water combined at 120°| 1·153|
+----------------------+------+
|Hydroscopic moisture | 1·422|
+----------------------+------+

The 'Chemical News' (xxxvi, 202) contains the analysis by Mr Paterson Muir of a clay from Mackenzie County, South Island, New Zealand, which is largely eaten by sheep. It consists of:--

+------------------+------+
|Silica | 61·25|
+------------------+------+
|Alumina | 17·97|
+------------------+------+
|Ferric oxide | 5·72|
+------------------+------+
|Lime | 1·91|
+------------------+------+
|Magnesia | 0·87|
+------------------+------+
|Sodium chloride | 3·69|
+------------------+------+
|Potassium chloride| trace|
+------------------+------+
|Water | 7·31|
+------------------+------+
|Organic matter | 1·77|
+------------------+------+
| |100·49|
+------------------+------+

See ANIMALCULÆ.

=EDULCORA'TION.= The affusion of water on any substance for the purpose of removing the portion soluble in that fluid. Edulcoration is usually performed by agitating or triturating the article with water, and removing the latter, after subsidence, by decantation or filtration. It is the method commonly adopted to purify precipitates and other powders which are insoluble in water. The washing-bottle is a most useful instrument for the edulcoration of precipitates. In its simplest form, it is a bottle fitted with two bent glass tubes, one drawn to a fine point and reaching to the bottom of the bottle, the other only entering the cork a few inches. By blowing down the latter tube, the water is forced out of the former in a fine stream. See WASH-BOTTLE.

=EEL.= _Syn._ ANGUILLA, L. A family of fishes belonging to the 'apodal' section of the _malacopterygii_. At least three species of eels are found in this country--the 'sharp-nosed,' the 'broad-nosed,' and the 'snig.' The first, which is common in streams and lakes, attains the greatest size--sometimes 25 lbs. or even 30 lbs. The 'snig' is considered superior to other kinds for the table. As articles of food, eels are said to be laxative and far from wholesome. The fat (EEL FAT; ADEPS ANGUILLÆ, OLEUM A.) is among the simples of the Ph. L. 1618, and was formerly considered 'good against stripes,' and is even now used by the vulgar as a friction for stiff joints. For the table, eels are generally dressed by stewing, frying, baking, or potting, which is done in the usual way, the fish being cut into pieces 2 or 3 inches long, and melted butter, onions, sweet herbs, and anchovy sauce, added at will. The CONGER EEL is a distinct and gigantic species of the same family. Its flesh is coarse and oily, but is much esteemed by the inhabitants of the southern coast of Devon, on which it abounds.

Letheby states the following to be the composition of the Eel:

+------------------+-----+
|Nitrogenous matter| 9·9|
+------------------+-----+
|Fat | 13·8|
+------------------+-----+
|Saline matter | 1·3|
+------------------+-----+
|Water | 75·|
+------------------+-----+
| |100·0|
+------------------+-----+

Payen's analysis differs from the above, in giving a larger proportion of nitrogenous matter, and a still greater quantity of fat.

The native inhabitants of New Zealand and kindred races suffer largely from scrofula, the prevalence of which disease amongst them has been attributed to their partaking so largely of eel as a common article of diet.

=EFFERVES'CENCE.= The rapid escape of gas in small bubbles from a liquid. See DRAUGHT, POWDER, &c.

=EFFLORES'CENCE.= The spontaneous conversion of a crystalline solid into a dry pulverulent form. Crystals which in a dry atmosphere lose their water of crystallisation, and become crusted over with a mealy powder, are said to be EFFLORESCENT.

=EGG.= _Syn._ OVUM, L. A body produced in the females of birds and certain other animals, containing an 'embryo' of the same species, or body, from which a similar animal may ultimately be produced. The eggs of the common domestic fowl are nutritious and easily digestible; and when lightly cooked by boiling and eaten with a little salt, are admirably adapted as an aliment for the sick and delicate. When boiled hard or fried, they are rendered less digestible, and possess no advantage in this respect over butcher's meat. A new-laid egg, beaten up in a cup of tea, coffee, or chocolate is an excellent ingredient in the breakfast of a person with a poor appetite, and is very supporting. A glass of wine, beer, or porter, similarly treated, along with a biscuit, has been recommended as a light and nutritious luncheon or supper, well suited to the debilitated and dyspeptic. Raw eggs may be advantageously substituted for cod-liver oil in all the cases in which this last is ordered, occurring in persons with delicate or irritable stomachs. The addition of fresh salad oil vastly increases their medicinal virtues. A fresh egg is said to contain about the same amount of nourishment as 1-1/2 oz. of fresh meat and 1 oz. of wheaten bread, but in a more digestible form.

_Composition of the contents of the egg._
Water 74·02
Albumen 14·08
Oil and fat 10·25
Mineral matter 1·65
-------
100·00

_Composition of the white of egg._ (Thompson.)
Nitrogenous matter 20·40
Fatty matter
Saline matter 1·60
Water 78·00
------
100·00

_Composition of the yolk._ (Thompson.)
Nitrogenous matter 16·00
Fatty matter 30·70
Saline matter 1·30
Water 52·00
------
100·00

=Egg, White of= (ALBUMEN OVI), is officinal in the B. P. Yelk of egg (_vitellus ovi_) is an ingredient in the BRANDY MIXTURE (MISTURA SPIRITUS VINI GALLICI) of the London College. It is also a popular application to chaps, cracked nipples, abrasions, &c., and is largely used to render oleaginous substances miscible with water, in the preparation of emulsions.

The average weight of the new-laid egg of a hen is about 2-1/2 oz., and its sp. gr. is 1·080 to 1·090; the white generally weighs about 1-1/2 oz.; the yolk, a little under 3/4 oz.; and the shell and skin, 1/4 oz. Dr Prout found that an egg, on being kept for 2 years in a dry situation, lost 544-3/10 gr., from the evaporation of a portion of its water through the shell. By boiling in water an egg loses from 2% to 3% of its weight.

_Choice._ The larger end of a new-laid egg feels cold when placed against the tongue. New-laid eggs appear semi-transparent when placed between the eye and a strong light, and have a small and perceptible division of the skin from the shell, which is filled with air. This mode of examination among the trade is called 'candling.' When they shake they are stale. The eggs of turkeys and pea-hens are much esteemed for some purposes; those of ducks and geese are coarse and inferior.

Sound eggs will sink if put into a solution, consisting of 1 oz. of salt in 10 oz. of water; in the same solution indifferent ones will float, whilst bad or worthless ones will swim even in pure water.

_Pres._ Eggs may be preserved for any length of time by excluding them from the air. One of the cleanest and easiest methods of doing this is to pack them with the small end downwards, in clean dry salt, in barrels or tubs, and to place them in a cool and dry situation. We have eaten eggs thus preserved that were more than a twelvemonth old, and that had been for some months on shipboard in a tropical climate, and which yet retained all the peculiar sweetness of new-laid eggs. With a like intention, eggs are placed in vessels containing milk of lime or strong brine, or are rubbed over with butter, lard, or gum water, all of which act by excluding the air. Eggs for keeping should never be laid on their sides, and when kept in the air should be occasionally turned to prevent the yolk attaching itself to the side instead of floating in the albumen. Some persons place the eggs in a netting or on a sieve or colander, and immerse them for an instant in a caldron of boiling water before packing them away. The practice of packing eggs in damp straw, or anything else that can convey a flavour should be carefully avoided. The shells of eggs are porous, and readily admit the passage of gaseous substances, especially of fetid odours. It is from inattention to this point that a large number of the eggs imported from the coast of France have a less delicate flavour than those of our poultry yards. Damp chopped straw, as well as most other organic substances exposed to warmth and moisture, readily ferment or putrefy; and during fermentation a considerable increase of temperature takes place, as any one may readily perceive by examining the common hotbeds in our gardens, which are merely masses of organic matter in a state of decomposition. Eggs, as long as they retain the embryo of the future chick in a vital state, possess in themselves a certain degree of warmth, which tends materially to promote the decomposition of the substances they are packed in, particularly in the presence of moisture.

A correspondent of the 'Chemical News' says: "Eggs may be kept fresh for a whole year by subjecting them to the following process. The fresh eggs are carefully placed in a mixture of five kilogrammes of alum, dissolved in five litres of water, heated to from 45° to 50° C., and left in that liquid for from thirty to forty minutes; the eggs are next drained, and in the meantime the solution of alum is heated to boiling-point. The eggs are again immersed in the liquid and kept therein from ten to fifteen seconds; after having been drained and cooled, they are packed in either dry bran, sawdust, cork-dust, sifted ashes, or in cotton-wool."

M. Durand, of Blois, proposes to preserve eggs by coating them with silicate of soda.

_To Preserve Eggs fresh for many weeks._--As the eggs are taken
from the nest, brush each one separately with a thin solution of
gum Arabic, being careful to leave no portion of the shell
uncovered by it. The half of each egg must first be done, and
left to become dry before the remainder is touched, that the gum
may not be rubbed off any part by its coming in contact while
wet with the hand as it is held to be varnished, or with the
table when it is laid down to harden.--ELIZA ACTON.

_Eggs to boil in the Shell._--Eggs brought from a cold place and suddenly plunged into boiling water are very frequently liable to crack, and thus to allow of the partial escape of their contents. In winter it will be found a good plan to hold them for an instant over the steam of the saucepan before they are placed in it, which they should be, very gently. By boiling for three minutes, the whites will become in a partially solid state. Exactly five minutes will harden the whites and leave the yolks liquid. Eight or ten minutes will render them hard. Eggs should always be boiled in water sufficient to entirely cover them. They should be boiled 15 minutes for salad-dressings.

_Eggs, to Poach._--Take for this purpose a wide and delicately clean pan about half filled with the clearest spring water; throw in a small saltspoonful of salt, and place it over a fire quite free from smoke. Break some new-laid eggs into separate cups, and do this with care, that the yolks may not be injured. When the water boils, draw back the pan, glide the eggs gently into it, and let them stand till the whites appear almost set, which will be in about a minute; then without shaking them move the pan over the fire, and just simmer them from two minutes and a half to three minutes. Lift them out separately with a slice, trim quickly off the ragged edges, and serve them upon dressed spinach or upon minced veal, turkey, or chicken; or dish them for an invalid upon delicately toasted bread, sliced thick and free from crust; it is an improvement to have the bread buttered, but it is less wholesome.

Comparative time of poaching eggs: swan's eggs, 5 to 6 minutes (in basin, 10 minutes); turkey's eggs, 4 minutes; hen's eggs, 3 to 3-1/2 minutes; Guinea fowl's, 2 to 3 minutes; bantam's, 2 minutes.

_Obs._ All eggs may be poached _without boiling_ if kept just at simmering point, but _one boil_ quite at last will assist to detach them from the stewpan, from which they should always be very carefully lifted on what is called a fish or egg slice. There are pans made on purpose for poaching and frying them in good form; but they do not, we believe, answer particularly well. If broken into cups slightly rubbed with butter and simmered in them, their roundness of shape will be well preserved.--ELIZA ACTON.

=Egg, Elas'tic.= Take a good and sound egg, place it in strong vinegar, and allow it to remain for 12 hours; it will then become quite soft and elastic. In this state it can be squeezed into a tolerably wide-mouthed bottle; when in, it must be covered with water having a little soda dissolved in it. In a few hours the egg will be restored to nearly its original solidity; after which the liquid may be poured off and the bottle dried, the whole being kept as a curiosity to puzzle one's friends for an explanation how the egg got there. ('Parlour Pastime.')

=Egg Flip.= _Prep._ 1. Beer, 1 pint; eggs, 3 in no.; sugar, 2 oz.; nutmeg and ginger, q. s. to flavour; the eggs are broken into one half of the beer, the sugar added, and the whole beaten well together; the mixture is then placed in a clean warmer, and heated over the fire to nearly the boiling-point, and stirred one way all the time, care being taken not to let it either boil or curdle; the other portion of the beer and the spices are then added, and the whole mixed well together.

2. As above, but adding a glass of spirit. Some persons also add a little lemon peel.

=Eggs, Packing, for Shipboard.= The following plan is now adopted by many firms shipping eggs:--"In the bottom of the box may be placed bran, cut hay, and sawdust. Tear up old newspapers to about 8 or 10 inches square. The paper should be about medium--that is, not too stiff nor too soft. Place one of these pieces of paper on the hand, and on this an egg, on one end; close the lower hand so as to bring the paper up all round the egg; with the other hand crumple the loose corners and edges of the paper down over the other end of the egg; lay another piece of paper on the hand, on which place the same egg, but the other end up; bring up the new paper and crumple down as before. This gives a good cushion to both ends, and a fair one over the centre. Repeat this till you have six thicknesses of paper, reversing the egg each time, and always keeping it on the end. This gives you a ball about 3 to 3-1/2 in. thick by 3-1/2 to 4 in. long. Care should be taken not to press the paper too closely to the egg while covering. Place on one end in the box or basket; place alongside and press them together close enough to prevent their becoming loose in the box, fillings at the ends and on top with crumpled paper."--J. P.

=Egg, Glaire of.= _Prep._ Separate the whites from the yolks, and whisk them to a froth, let them stand 24 hours, and strain them through muslin. Used as a glaze or varnish by bookbinders and others.

=Egg, Liquid.= _Prep._ (Jayne.) From lime, 1 bushel (slaked with water); common salt, 2 or 3 lbs.; cream of tartar, 1/2 lb.; water, q. s. to form a mixture strong enough to float an egg. Used to preserve eggs, which it is stated it will do for two years, by simply keeping them in it. Simple milk of lime answers quite as well.

=Egg Wine.= As egg flip, but using equal parts of white wine and water, instead of beer.

=ELA'IDINE.= A fatty compound of elaïdic acid and glycerin, formed by the action of nitrous acid or nitrate of mercury on olive oil. It is neutral; melts at 90° Fahr.; and is very soluble in ether, scarcely so in alcohol. It is one of the components of CITRINE OINTMENT. By saponification it is resolved into its two constituents.

=ELA'IN.= See OLEIN.

=ELAIOM'ETER.= _Syn._ OLEOM'ETER. An instrument for ascertaining the specific gravity of oils. See HYDROMETER and OIL.

=ELAL'DEHYD.= A peculiar crystalline substance which forms in ALDEHYD when kept for some weeks at a temperature of 32° Fahr. It melts into a colourless liquid at about 38°, in which state it is miscible with water, alcohol, and ether. It is isomeric with aldehyd, but its vapour has about three times the density of that substance, whilst it neither combines with ammonia nor comports itself with potassa and solution of silver like aldehyd.

=ELAOP'TENE.= See OIL (Volatile).

=ELAT'ERIN.= _Syn._ MOMORDICINE. The active principle of ELATERIUM. It was discovered by Dr Clutterbuck in 1819, but first obtained in a state of purity in 1830 by the late Mr Hennel.

=Elaterin.= _Syn._ ELATERIUM. (Dr Morries.) Obtained by evaporating tincture of elaterium (made with rectified spirit) to the consistence of thin oil, and throwing it in boiling distilled water. When cold, the crystalline precipitate is collected, and dried with a gentle heat.--_Dose_, to commence with 1-16th of a grain.

_Prep._ 1. (Dr Morries.) Elaterium is digested in hot alcohol, the resulting tincture filtered, evaporated to the consistence of thin oil, and then thrown into boiling distilled water. When the whole is cold, the precipitate is collected and purified by redissolving it in alcohol and precipitation by water, as before.

2. (Hennel.) The alcoholic extract of elaterium is digested in ether, and the residuum dissolved in hot alcohol; crystals form as the solution cools.

3. An alcoholic tincture is evaporated to the consistence of a syrup, and thrown into a mixture of equal parts of liquor of potassa and water at a boiling temperature. Almost pure elaterin separates as the liquid cools.

_Obs._ Elaterin forms delicate, white, silky crystals, having a bitter taste; it is fusible at about 365° Fahr.; tastes bitter; odourless; neutral; insoluble in water; and dissolves readily in hot alcohol. Its medicinal action is similar to that of elaterium, differing only in its greater activity.--_Dose_, 1/16 gr. to 1/20 gr.

=ELATER'IUM.= _Syn._ SQUIRTING CUCUMBER. In _pharmacy_, 'the fresh unripe fruit' of the wild cucumber, '_Ecbalium officinarum_--Richard,' Ph. L. (_Momordica Elaterium_, Linn.). According to present usage, the word is more generally applied to the feculence deposited from the juice of the wild cucumber. It is thus applied in Ph. B. E. & D. See _below_.)

=Elaterium.= B. P. _Syn._ EXTRACT OF ELATERIUM, E. OF SQUIRTING CUCUMBER; EXTRACTUM ELATERII (Ph. L.), ELATERIUM (Ph. E. & D.,) L. The feculence of the juice of the above fruit.

_Prep._ 1. (Ph. L.) Slice wild cucumber before it is quite ripe in the long direction, and strain the juice, very gently expressed, through a fine hair sieve; then set it aside for some hours, until the thicker part has subsided. The thinner supernatant fluid being rejected, dry the thicker portion with a gentle heat. The processes of the other colleges are essentially the same.[272]

[Footnote 272: At the Mitcham Gardens, elaterium is manufactured in much the same way, only that considerable force is used in the expression of the juice, and the product therefore less potent, though more in quantity. The manufacture usually commences about the second week in September. (Dr Royle).]

2. (Dr Clutterbuck.) The cucumbers (fully ripe) are cut longitudinally, and sprinkling with cold water, and the juice allowed to strain through a fine sieve into an earthenware vessel. The seeds and surrounding pulp are next placed on the sieve, with the split fruit, and washed repeatedly with cold water. The washings being received in the same vessel with the juice, the whole is allowed to repose for a few hours, when the clear portion is decanted and the sediment spread thinly on fine linen, and dried by exposure to the air and a gentle heat avoiding the sunshine or a bright light. Quality very fine. Forty fruits, by this process, yield only 6 gr. of elaterium.

3. (Apothecaries' Hall.) The fruit, slit into halves, is placed in hempen or horsehair bags, and submitted to slight pressure in a tincture press. The juice, as it runs off, passes through a fine hair sieve into a cylindrical glass jug or jar, where it is allowed to remain for two hours, when the clear supernatant liquor is poured off, and the thick portion containing the sediment is poured on a paper filter, supported on linen, and allowed to drain, after which it is dried by a gentle heat in a stove. The product has a green colour, and constitutes the finest elaterium of commerce. A darker and inferior article is obtained from the liquor, poured from the first sediment by placing it in shallow pans, and allowing it again to deposit.

_Prop., &c._ Elaterium is sold in thin cakes, and when pure has a pale-gray or greenish-gray colour, floats on water, is easily pulverised by pressure, and forms with rectified spirits a rich, green-coloured tincture. Elaterium obtained as a second deposit (ELATERIUM NIGRUM), is dark and inferior. Alcohol dissolves from 50% to 60% of good elaterium. "When exhausted by rectified spirit, the solution, concentrated, and poured into hot dilute solution of potassa, deposits, on cooling, minute silky, colourless crystals (of ELATERIN), weighing from 1/7th to 1/4th of the elaterium operated on." (Ph. E.)

_Obs._ To procure a fine sample of elaterium it is necessary to remove it as soon as it is deposited, as a heavy mucilage falls down soon afterwards, which materially injures its quality and appearance. English elaterium is the best. The foreign is uniformly adulterated with chalk or starch, and coloured with sap green.

_Dose_, 1/16 gr. to 1/2 gr., formed into a pill with extract of gentian and liquorice powder; as a hydragogue and cathartic in dropsies, twice a day, repeated every other day for a week or ten days. Its use must be avoided when there is much debility or any inflammatory symptoms. Larger doses than 1/2 gr. of pure elaterium are poisonous. The _antidotes_ are emetics, followed by demulcents, opium, and stimulants.

=EL'DER.= _Syn._ SAMBUCUS (Ph. L. & E.), L. A large shrub or small tree belonging to the natural order _Caprifoliacæ_. It is indigenous in Europe, and has long been valued for its medicinal properties. "The recent flowers of the _Sambucus nigra_" (Ph. L.) or common elder are regarded as diaphoretic and pectoral, and a distilled water (ELDER-FLOWER WATER; AQUA SAMBUCI) is made of them. The inner bark of the same tree is purgative and emetic, and is used in dropsy; the leaves are purgative; the juice of the fresh berries is made into wine (ELDER WINE), and is largely used to make FACTITIOUS PORT WINE, and to adulterate the real wine. See WATERS (Distilled).

=ELECAMPANE'.= _Syn._ INULA (Ph. L.), L. "The root of _Inula Helenium_" (Ph. L.). A plant of the nat. order _Compositæ_. Tonic, diaphoretic, and expectorant.--_Dose_, 20 gr. to 1 dr., or more, either in the form of powder or decoction; in catarrh, dyspepsia, &c. It is now seldom used.

=ELECTRANODYN.= For the cure of neuralgia, headache, migrain, faceache, and apoplectic attacks. As a necklace for children for toothache, as a preventive of quinsy, &c. A tissue paper converted into a nitrogenous material (pyroxylin or _düppelpapier_) by immersion in a mixture of sulphuric and nitric acid, and containing besides an insignificant proportion of wax and resin. (Hager.)

=ELEC'TRIC.= _Syn._ ELECTRICAL. Exhibiting the effects of ELECTRICITY when 'excited' by friction; pertaining to, derived from, or produced by electricity.

=Electric.= _Syn._ INSULATOR, NON-CONDUCTOR. A substance which may under ordinary circumstances be readily made to evince electrical properties by friction. Electrics do not transmit, or conduct, electricity; whilst, on the other hand, ANELECTRICS are good transmitters or conductors of electrical action. The most perfect electrics are shell-lac, sulphur, amber, jet, resinous bodies, gums, gun-cotton, glass, silk, diamond, agate, and tourmaline; dry fur, hair, wood, feathers, and paper; turpentine and various oils; dry atmospheric air and other gases, steam of high elasticity, and ice at 0° Fahr. The most perfect anelectrics or conductors are the metals, charcoal, and saline fluids.

=Electric Eel.= The _Gynotus electricus_, a fish having the power or giving violent electric 'shocks'; which power it exerts for killing or stunning its prey. It is an inhabitant of the fresh-water lakes and rivers of the warmer regions of America, Africa, and Asia.

=Electrical Machine.= An instrument for the excitation and collection of electricity. The term is only applied to contrivances in which friction is the immediate cause of the electrical disturbance; those which act through chemical force, magnetism, or heat, being known by various distinctive names, as 'voltaic battery,' 'electro-magnetic machine,' 'induction-coil,' 'thermo-electric pile,' &c.

The electrical machines in common use are composed of a hollow glass cylinder, or circular plate of glass, turning on an axis, and rubbing against two or more leather rubbers covered with silk, the electricity being collected by sharp points fixed in a metal rod standing on a glass pillar. A description of these instruments, however, would be out of place in the present work, which does not aim at giving information that may be easily obtained from other sources.

Cylinder machines are seldom made of greater size than 13 inches by 9, and are about as powerful as an 18-inch plate machine. The latter are commonly made up to 3 and 4 feet diameter, and will, with a suitable condenser, give 15 inch sparks in air.

=ELECTRI''CITY= (-tr[)i]s'-[)i]t-e). The name given primarily to one of the great forces of nature, and secondarily to that department of physical science which embraces all that is known respecting this particular force. Many theories respecting the nature of electricity have been advanced for the purpose of explaining electrical phenomena. The theory of Dr Franklin supposed the existence of a single homogeneous, imponderable fluid, of extreme tenuity and elasticity, in a state of equable distribution throughout the material world. This fluid is assumed to be repulsive of its own particles, but attractive of all other matter. When distributed in bodies, in quantities proportionate to their capacities or attraction for it, such bodies are said to be in their 'natural state.' When we increase or diminish the natural quantity of electricity in any substance, excitation is the result, and the substance, if 'overcharged,' is said to be electrified 'positively,' or if 'undercharged,' 'negatively.' These theories, and all others based upon the assumption that electricity is a form of matter, have been found to be inadequate for the elucidation of electrical phenomena.

At the present day, however, two kinds of electric forces are recognised, and distinguished as negative and positive, but they are both assumed to be analogous in principle, and very generally assumed to be simply due to different analogous motions of matter. For a full exposition, however, the reader must refer to some of the especial works on the subject.

=ELECTRICITY, Iron reduced by.= Gelatin capsules of the size of a 2-grain pill, filled with powdered blacksmith scales (black oxide of iron). (Hager.)

=ELECTRO-CHEM'ISTRY.= That branch of chemistry which treats of the agency of electricity in effecting chemical changes.

=ELECTRO-ETCH'ING.= See ETCHING.

=ELECTROL'YSIS.= (-tr[)o]l'-e-s[)i]s). Electro-chemical decomposition. The voltaic current has the power of loosening and separating the constituents of certain compound bodies when these are interposed in the circuit. The substances which are thus susceptible of decomposition are termed electrolytes. They are all binary compounds, containing single equivalents of their components, which are held together by very powerful affinities. The amount of electrical power required to effect decomposition varies greatly with different electrolytes: solution of iodide of potassium, melted chloride of lead, hydrochloric acid, water mixed with a little sulphuric acid, and pure water, demand very different degrees of decomposing force, the resistance increasing from the first-mentioned substance to the last, which latter it has been denied can be decomposed. One of the indispensable conditions of electrolysis is fluidity. When a liquid is electrolysed its components are discharged solely at the limiting surfaces, where, according to the usual figurative mode of speech, the current enters and leaves the liquid, all the intermediate portions appearing quiescent. The terms 'anode' and 'cathode' have been proposed respectively for the surfaces which are supposed to receive and let out the current of positive electricity. The anode is therefore directly against or opposite the positive pole of the battery, or, according to the improved nomenclature, the positive electrode; and the cathode against the negative pole, or electrode. The bodies which are set free by the action of the current are termed ions; those which go to the anode and appear at the positive electrode being distinguished by the term anions, and those which go to the cathode and appear at the negative electrode by the term cathions. This nomenclature has, however, been but partially adopted, and is making but slow way, if any, many preferring the old terms of electro-positive for anions, and electro-negative for cathions.