Chapter LXIII: Part 2 (24)

Various observers have arrived at different conclusions respecting the amount of carbonic acid exhaled from the skin. Professor Scharling believed it to be from a fortieth to a sixtieth the amount given off by the lungs. Recent observations seem, however, to have shown that this estimate was too high. Dr Edward Smith, operating upon himself by placing every part of his body except the head in a caoutchouc bag, and subsequently collecting the evolved carbonic acid (the experiment being performed in the summer time), found the quantity evolved to be 6 grains per hour, or about a hundredth part of that passing off from the lungs.

Aubert’s experiments led him to the conclusion that it was about half the amount given by Smith; whilst Reinhart estimated it at 34 or 35 grains a day.

These excretory processes of the skin are effected by means of very minute vessels called the _sudoriparous_ or _sweat-glands_. These glands abound in almost every part of the human skin. They are of largest size under the axillæ or arm-pits, where perspiration is most profuse. They are also very abundant upon the palms of the hand. Professor Erasmus Wilson says that as many as 3528 of these sweat-glands exist in a square inch of surface on the palm of the hand; and as every tube, when straightened out, is about a quarter of an inch in length, it follows that, in a square inch of skin from the palm of the hand, there exists a length of tube equal to 882 inches, or 73-1/2 feet. These glands, as we have seen, vary in number for different parts of the human body; but if we take Professor Wilson’s average for the superficial area of a man of ordinary stature, viz., 2800 of them to the square inch, it follows “the total number of pores on such a man’s skin would be about _seven millions_, and the length of perspiratory tubing would then be 1,750,000 inches, or 145,833 feet, or 48,611 yards, or nearly 28 miles.”[166]

[Footnote 166: Carpenter’s ‘Human Physiology.’]

In addition to the _sudoriparous_, the skin also possesses _sebaceous_ glands which stud almost every part of its surface except the palms of the hands and the soles of the feet. The sebaceous glands secrete a semi-fluid, greasy kind of substance, the office of which is probably to aid in rendering the skin soft and supple, and to prevent the too rapid evaporation of moisture from it. The sebaceous glands are more particularly found on the scalp, the anus, and the nose, their locality in the skin of this last feature being sometimes marked by small black specs, which when squeezed yield a little white mass resembling a maggot in appearance. This is merely the solidified secretion from the sebaceous gland. A parasite known as the _Acarus folliculorum_ infests the sebaceous glands. In the cartilaginous part of the external passage of the ear are other glands, the _ceruminous_, which secrete the wax that forms a protective film for the membrane of the tympanum or drum, and guards it against dust, insects, &c. See EXERCISE, PERSPIRATION.

=SKIN BALSAM, Glycerin——Glycerin Haut, Balsam.= A mixture of 1000 parts glycerin, 120 parts orange-flower water, 1 part each oils of neroli and bitter almonds. (Hager.)

=SKIN COSMET′ICS.= The simplest, cheapest, and most generally employed cutaneous cosmetics are soap and water, which at once cleanse and soften the skin. Soap containing a full proportion of alkali exercises a solvent power upon the cuticle, a minute portion of which it dissolves; but when it contains a small preponderance of oily matter, as the principal part of the milder toilet soaps now do, it mechanically softens the skin and promotes its smoothness. Almond, Naples, and Castile soaps are esteemed for these properties, and milk of roses, cold cream, and almond powder (paste), are also used for a similar purpose. To produce an opposite effect, and to harden the cuticle, spirits, astringents, acids, and astringent salts, are commonly employed. The frequent use of hard water has a similar effect. The application of these articles is generally for the purpose of strengthening or preserving some particular part against the action of cold, moisture, &c.; as the lips, or mammæ, from chapping, or the hands from contracting chilblains; but in this respect oils, pommades, and other oleaginous bodies, are generally regarded as preferable.

Another class of cutaneous cosmetics are employed to remove freckles and eruptions. Among the most innocent and valuable of these is Gowland’s lotion, which has long been a popular article, and deservedly so, for it not only tends to impart a delightful softness to the skin, but is a most valuable remedy for many obstinate eruptive diseases which frequently resist the usual methods of treatment. Bitter almonds have been recommended to remove freckles (Celsus), but moistening them with a lotion made by mixing 1 fl. oz. of rectified spirit, and a teaspoonful of hydrochloric acid with 7 or 8 fl. oz. of water, is said to do this more effectually. A safe and excellent cosmetic is an infusion of horseradish in cold milk. (Withering.)

Hermann prescribes the following lotion:——Blanched almonds, 2 oz.; rose water, 8 oz.; orange-flower water, 2 oz. Make an emulsion, strain, and add sal ammoniac, 1 dr.; simple tincture of benzoin, 2 dr.

Skin paints and skin stains are employed to give an artificial bloom or delicacy to the skin. Rouge and carmine are the articles most generally used to communicate a red colour. The first is the only cosmetic that can be employed, without injury, to brighten a lady’s complexion. The other, though possessing unrivalled beauty, is apt to impart a sallowness to the skin by frequent use. Starch powder is employed to impart a white tint, and generally proves perfectly harmless. The American ladies, who are very fond of painting their necks white, use finely-powdered magnesia, another very innocent substance. Several metallic compounds, as the trisnitrate, chloride, and oxide of bismuth (pearl white, Fard’s white, &c), carbonate of lead (flake white), white precipitate, &c., are frequently used to revive faded complexions; but they are not only injurious to the skin, but act as poisons if taken up by the absorbents. Trisnitrate of bismuth (pearl white), probably the least injurious of these articles, has been known to cause spasmodic tremblings of the muscles of the face, ending in paralysis. (‘Voght. Pharm.’) The employment of liquid preparations containing sugar of lead, which are commonly sold under the name of milk of roses, cream of roses, &c., is equally injurious. Another disadvantage of these metallic preparations is, that they readily turn black when exposed to the action of sulphuretted hydrogen gas, or the vapours of sulphur, such as frequently escape into the apartment from coal fires. There are many instances recorded of a whole company being suddenly alarmed by the pearly complexion of one of its belles being thus transformed into a sickly grey or black colour.

In conclusion, it may be remarked that the best purifiers of the skin are soap and water, followed by the use of a coarse but not a stiff cloth, in opposition to the costly and smooth diapers that are commonly employed; and the best beautifiers are health, exercise, and good temper.

=Skin, Goldbeat′er’s.= See GOLDBEATER’S SKIN.

=SKINS (of Animals).= The preparation and preservation of fur skins are noticed under PELTRY; the preparation and uses of the skins of the larger animals under LEATHER, TANNING, TAWING, &c.

=SLACK.= Small coal, such as is used for kilns.

=SLAG.= The semi-vitrified compounds, produced, on the large scale, during the reduction of metallic ores by fluxes. Those from iron and copper works are often used for building materials, mending roads, &c.

According to Egleston[167] the following are some of the industrial applications to which the slag from blast furnaces is put.

[Footnote 167: Dingler’s ‘Polytech. Journ.,’ ‘Journ. Chem. Society.’]

When required for building stones the slag is run from the blast furnace into a semicircular vessel on moving wheels, and having its bottom covered three centimetres deep with sand and coke dust. By means of a bent iron instrument the slag is mixed with sand and coke dust till the escape of gases has nearly ceased and the mass is sufficiently tough. With the same tool it is next pressed into a mould furnished with a lid, which is forced down as soon as the escape of gas ceases. The red-hot stone is then placed in the cooling oven, covered with coke dust, and allowed to remain three or four days to cool completely. These stones are impervious to damp, and make good foundations. According to another method the slag, which should contain from 38 to 44 per cent. of silica, is run down a shoot into a large cavity, and then covered over with sand and ashes, and left to cool from five to ten days, when it is distributed in moulds, and there hardens. In certain parts of Belgium slag is poured upon iron plates and cooled by water, and thus a kind of glass is manufactured.

In other districts the slag is granulated as it flows from the blast furnace by means of a stream of water. The granulated slag is preferred by the puddlers to the sand for the moulds of pig iron. The slag gravel may be advantageously substituted for sand in mortar making, a more rapid hardening being thus secured, a matter of great moment in building foundation walls.

Artificial stone is also manufactured from the granulated slag, and used for building purposes, furnishing warm dry houses of handsome appearance.

When stones for building with enamelled surfaces are required they are obtained in some parts of Europe as follows:——The unburnt bricks are covered with granulated slag, and after drying are burnt in a furnace where they do not come in contact with carbon. The stones are completely glazed, and according to the different kinds of slag used are tinted of different colours. This operation is also employed advantageously with tiles, pipes, and earthenware.

If, in the preparation of fire-proof bricks, a certain proportion of mixture of clay and granulated slag be added to the mixture, very hard and durable fire bricks are obtained. These have been tested in a brass furnace, and experiments are being tried as to their applicability to building puddling furnaces. This granulated slag may also be advantageously used for manure. Blast furnace slag has also been drawn out in fine threads or filaments, furnishing the so-called ‘furnace wool.’ This substance, being a very bad conductor of heat, has suggested various household and other uses. A cheap and valuable cement, said to be equal to Portland cement, has been prepared from the finely granulated slag, which will also resist well the action of acids.

Mr Britten in 1876 patented a process for the manufacture of glass from blast furnace slag. Large works for the purpose of carrying out this invention, under the title of ‘Britten’s Patent Glass Company,’ have been erected at Finedon in Northamptonshire, and are, we believe, successfully worked in manufacturing glass bottles.

The method consists in removing molten slag in a ladle from the blast furnace, and pouring into a Siemen’s furnace, when certain amounts of carbonate of sodium and silica are added, depending upon the quality of the slag used, and of the glass required.

=SLATE.= The excellence of this material for water cisterns deserves a passing notice here.

Irish slate (_Lapis Hibernicus_) is an argillaceous mineral, said to contain iron and sulphur, found in different parts of Ireland. It is a common remedy, among the vulgar, for internal bruises, taken in a glass of gin.

=SLEEP.= During the period of our waking hours the exercise of the animal functions entails a waste or destruction of tissue in the organs performing them, which, unless duly repaired, would soon lead to the enfeeblement and consequent failure of the powers of the organs themselves. For the animal economy therefore to be maintained in a state of efficiency the repair of the reduced tissues is a necessity; and this essential condition is effected by the agency of sleep, during which respiration, circulation, digestion, &c., continue to be carried on simultaneously with assimilative processes which end in the regeneration of the impaired tissue.

A proper amount of sleep is therefore as great or even a greater necessity than a proper supply of food; and any one failing to obtain it soon perishes of exhaustion. Thus it is that any great mental emotion——such as intense remorse, grief, anxiety, or the depressing effect of a reverse of fortune——so frequently expedites death. Like Macbeth “it murders sleep,” one of the great needs of man’s existence.

Infants and children it is well known require much more sleep than adults. In these latter the organism, being already matured, demands only so much sleep as will enable it to make up for the daily waste of the body, which waste falls very far below the amount of nutrition required by the growing infant. In a still earlier state of development, viz., the fœtal one, life may be said to be passed entirely in slumber; whilst children prematurely born scarcely ever wake except for food. We may assume that, as a general rule, infants take treble the amount of sleep that adults do, and that very young infants thrive the better the larger the amount of sleep they get, is borne out by the experience of medical practitioners, who affirm that they have known many children who were born small and weakly, but who slept the greatest part of their early existence, afterwards became strong and healthy; whilst those children on the contrary who, being born large and strong, were not good sleepers, became subsequently enfeebled and unhealthy. As regards the sleep of adults, if the slumber has been of average length, or the subject of it awakes fully refreshed therefrom, a second sleep instead of being conducive is prejudicial to health, and should never be encouraged.

During sickness a patient, if in a very helpless and enfeebled state, may often be exposed whilst asleep to great peril, unless the nurse who attends him exercises intelligence and a proper amount of vigilance. In his work on ‘Household Medicine’ Dr Gardner has pointed out the dangers that beset the sleeping patient, and the means by which they may be avoided. “Having disposed,” he says, “of the patient in bed in the best manner, be careful that no part of the pillow can project over the mouth or nose, and that the bedclothes do not cover the mouth.

“The attendant should be particularly attentive to these points, when a narcotic has been taken, when the disease is paralysis, fever, head diseases, bronchitis, or any pulmonary complaint. The patient should be watched until he sleeps, and during his sleep, if a nurse is not constantly present, should be visited frequently, to observe whether the mouth and nostrils are free, and nothing obstructs the breathing.

“Very little suffices for an obstruction in such cases, which may extinguish life. Hundreds, perhaps we may say thousands of persons die prematurely from suffocation during sleep, in a low condition of the vital energies.

“How often does it happen that a patient left in a calm sleep is found dead upon being visited an hour or two after. Soft yielding pillows, in which the head and face get buried, are the instruments of suffocation to weakly persons, very, very often.”

The larger amount of sleep indulged in by the very old, over adults, is referable to the incapacity of the aged for exercise, and to their enfeebled powers of nutrition. Besides age, temperament, habit, and surrounding circumstances exercise considerable influence on the amount of sleep necessary for man. Persons of lymphatic temperament are generally great sleepers; whilst those of a nervous and active nature are mostly the reverse. The late Earl Russell was we believe in the years of his active political life a very small sleeper, his slumbers seldom extending over five hours. So, likewise was the Duke of Wellington; General Elliott, the defender of Gibraltar, seldom slept more than four hours out of the twenty-four. As a contrast to these cases may be mentioned that of Dr Reid, the metaphysician, of whom it is stated that he could take as sufficient food and afterwards as much sleep as would suffice for an ordinary man for two days.

Several well-attested cases of excessive slumber are on record in which the sleep lasted in some cases for weeks, and in others even for months.

In the ‘Comptes Rendus’ for 1864 Dr Blanchet records the case of one of his patients, a lady of 24 years of age, who had slept for 40 days when she was 18 years of age. Two years later she had a sleep lasting 50 days. Upon a subsequent occasion she fell asleep on Easter Sunday, 1862, and did not wake till March, 1863. She was fed during this period with milk and soup. She continued motionless and insensible, the pulse was low, the breathing scarcely perceptible, there were no evacuations, and she betrayed no signs of wasting away, whilst her complexion is described as florid and healthy.

This, however, as well as other cases of a similar kind, must not be regarded as an extreme instance of healthy slumber, but as a form of lethargy or coma, as indicative of disease, as the opposite condition or sleeplessness, that is frequently an accompaniment of certain forms of fevers, inflammatory affections, and brain disorders.

Mr Durham, of Guy’s Hospital, seems to have disposed of the condition that sleep is caused by the pressure of the distended veins on the brain.

A piece of bone being removed from a dog’s skull so that the animal’s brain could be observed when sleeping, it was found, 1, the veins were not distended. 2. During sleep the brain is in a comparatively bloodless condition, and the blood in the encephalic vessels is not only diminished in quantity, but moves with diminished rapidity; and this is corroborated by the observations of Dr Hughlings Jackson on the ophthalmoscopic condition of the retina during sleep, the optic disk being then whiter, the arteries smaller, and the retina generally more anæmic than in the waking state. 3. The condition of the cerebral circulation during sleep is from physical causes, that which is most favorable to the nutrition of the brain tissue. See BED, WATCHFULNESS.

=SLEEPLESSNESS AND COLD FEET.= The association betwixt cold feet and sleeplessness is much closer than is commonly imagined. Persons with cold feet rarely sleep well, especially women. Yet the number of persons so troubled is considerable. We now know that if the blood-supply to the brain be kept up, sleep is impossible. An old theologian, when weary and sleepy with much writing, found that he could keep his brain active by immersing his feet in cold water; the cold drove the blood from the feet to the head.

Now, what this old gentleman accomplished by design is secured for many persons much against their will. Cold feet are the bane of many women. Light boots keep up a bloodless condition of the feet in the day, and in many women there is no subsequent dilatation of the blood-vessels when the boots are taken off. These women come in from a walk and put their feet to the fire to warm——the most effective plan of cultivating chilblains. At night they put their feet to the fire, and have a hot bottle in bed. But it is all of no use; their feet still remain cold. How to get their feet warm is the great question of life with them——in cold weather. The effective plan is not very attractive at first sight to many minds. It consists in first driving the blood-vessels into firm contraction, after which secondary dilatation follows. See the snowballer’s hands! The first contact of the snow makes the hands terribly cold; for the small arteries are driven thereby into firm contraction, and the nerve-endings of the finger-tips feel the low temperature very keenly. But as the snowballer perseveres, his hands commence to glow; the blood-vessels have become secondarily dilated, and the rush of warm arterial blood is felt agreeably by the peripheral nerve-endings. This is the plan to adopt with cold feet. They should be dipped in cold water for a brief period; often just to immerse them, and no more, is sufficient; and then they should be rubbed with a pair of hair flesh gloves, or a rough Turkish towel, till they glow, immediately before getting into bed. After this a hot-water bottle will be successful enough in maintaining the temperature of the feet, though without this preliminary it is impotent to do so. Disagreeable as the plan at first sight may appear, it is efficient; and those who have once fairly tried it continue it, and find that they have put an end to their bad nights and cold feet. Pills, potions, lozenges, “night-caps,” all narcotics, fail to enable the sufferer to woo sleep successfully: get rid of the cold feet, and then sleep will come of itself.——_British Medical Journal._

=SMALLPOX.= See POX.

=Smallpox in Sheep.= _Syn._ VARIOLA OVINA. This disease, although bearing the same name as that which attacks the human subject, is a perfectly distinct malady, and incapable of being communicated to man either by inoculation or contagion. In about ten days from the time of the animal’s having imbibed the contagion feverish symptoms set in accompanied with a mucous discharge of a purulent character from the nose. Red inflammatory pimples then begin to develop, first appearing where the skin is thin. After the pimples have been out about three days they assume a white appearance, and are filled with serum and pus. “Some of the vessels dry up, leaving brown scabs; others, especially in the severer cases, run together, and the scarf skin is detached, leaving an ulcerated surface. It is in this ulcerated stage that the prostration reaches its height, and that most sheep die. The mortality from smallpox in sheep ranges from 25 to 90 per cent.”[168]

[Footnote 168: Finlay Dun.]

The disease being a very infectious one, the affected animals must be kept separate from the healthy ones. Thirty grains of chlorate of potash should be given three times a day, whilst the food should be nutritious and such as to tempt the animal’s appetite. It may consist of bruised oilcake, bran, and steeped oats. Professor Simonds recommends inoculation as a prophylactic measure.

=Smallpox Marks, Prevention of.= 1. For preventing disfigurement from smallpox marks, Dr Bernard suggests that the pustules as soon as they have acquired a certain size should be punctured with a fine needle, and then repeatedly washed with tepid water.

2. Dr Thorburn Patterson prescribes the following ointment:——Carbonic acid, 20 to 30 minims; glycerine, 1-1/2 dr.; ointment of oxide of zinc, 6 dr.

3. Cream smeared on the pustules, frequently during the day, with a feather. See also OINTMENTS.

=SMALTS.= _Syn._ AZURE, POWDER BLUE, SILICEOUS B., SMALT, AZURUM, SMALTA, L. This consists, essentially, of glass coloured by fusing it with oxide of cobalt.

_Prep._ 1. Cobalt ore is roasted, to drive off the arsenic, then made into a paste with oil of vitriol, and heated to redness for an hour; the residuum is powdered, dissolved in water, and the ferric oxide precipitated with carbonate of potassium, gradually added, until a rose-coloured powder begins to fall; the clear portion is then decanted, and precipitated with a solution of silicate of potassium (prepared by fusing together, for 5 hours, a mixture of 10 parts of potash, 15 parts of finely ground flints, and 1 part of charcoal); the precipitate after being dried is fused, and reduced to a very fine powder. A very rich colour.

2. Roasted cobalt ore and carbonate of potassium, of each 1 part; siliceous sand, 3 parts; fuse them together, and cool and powder the residuum. Used as a blue pigment, also to colour glass, and for ‘blueing’ the starch used to get up linen. See BLUE PIGMENTS.

=SMELL′ING SALTS.= See SALTS, SMELLING.

=SMELT.= A beautiful little abdominal fish abounding in the Thames, and a few other rivers, between the months of November and February. It is esteemed a great delicacy by epicures, but sometimes proves offensive to the delicate and dyspeptic.

=SMOKE PREVEN′TION.= Although the full consideration of this subject belongs to public hygiene and civil engineering, its immediate application and advantages are interesting and important to everybody.

The history of smoke burning scarcely commences before the year 1840, at which date Mr Charles Wye Williams obtained a patent for this purpose. Since that time a ‘thousand-and-one’ schemes, either patented or non-patented, professedly for the same object, have been brought before the public. Most of these have been supported by the most reckless statements regarding their value, made by interested parties; and the most serious inconvenience and losses have often followed their adoption. Williams’s method is to admit an abundant supply of cold air through a large number of small perforations in the door and front part of the furnace. Lark’s method is based on the admission of heated air, under due regulation, both through the door, and at the bridge or back of the furnace, by which means combustion is rendered more complete, and smoke thereby prevented.

Ivison’s plan consists in the introduction of steam by minute jets over the fire, which is thus greatly increased in intensity without the production of smoke, and with a saving of fuel. In Jucke’s arrangement the grate bars of a furnace are replaced by an endless chain web, which is carried round upon two rollers, in such a way that each part of the fuel is exposed to conditions most favorable for perfect combustion. Other inventions are based upon supplying fuel to the fires from beneath, so that the products of combustion must pass through the incandescent coals above.

For household fires, the smokeless grate, invented by Dr Arnott, will be found entirely successful, and most economical. Its general introduction would be a great advance in both domestic and public hygiene; and, being hence of national importance, should be enforced by law.

=SMO′′KING.= This is done, on the large scale, by hanging up the articles (previously more or less salted) in smoking rooms, into which smoke is very slowly admitted from smothered dry-wood fires, kindled in the cellar, for the purpose of allowing it to cool and deposit its cruder part before it arrives at the meat. This process requires from six days to as many weeks to perform it properly, and is best done in winter. In farm-houses, where dry wood is burnt, hams, &c., are often smoked by hanging them up in some cool part of the kitchen chimney. When the meat is cut into slices, or scored deeply with a knife, to allow the smoke to penetrate it, it is called ‘BUCANING,’

“The quality of the wood has an influence upon the smell and taste of the smoke-dried meat; smoke from beech wood and oak being preferable to that from fir and larch. Smoke from the twigs and berries of juniper, from rosemary, peppermint, &c., impart somewhat of the aromatic flavour of these plants.” (Ure.) The occasional addition of a few cloves or allspice to the fuel gives a very agreeable flavour to the meat.

Hung beef, a highly esteemed variety of smoked beef, is prepared from any part, free from bone and fat, by well salting and pressing it, and then drying and smoking it in the usual manner. It is best eaten shredded. See PUTREFACTION, SALTING, &c.

=SNAKE-POISONING, Mortality from.= The ‘Lancet’[169] quoting a letter from T. B. Beighton, Esq., of the Bengal Civil Service, magistrate of the Culna district of the Burdwan province of Bengal, says:——“The Culna district comprises, we presume, 80 or 100 square miles, and has a population of about 300,000. Mr Beighton says that deaths from snakebite are singularly common in the subdivision. An average of one per day is reported through the police. The actual deaths are probably double the number reported. If this daily average is meant to apply the whole year round, we should thus get in a comparatively small district the frightful death of 700 persons from snakebite. It is lamentable to think that despite the supposed remedial discoveries in this direction, we still seem to be without an agent to neutralise the effects of the bites of poisonous snakes.”

[Footnote 169: ‘Analyst,’ 11th, 1870.]

=SNAKE-ROOT.= See SENEGA. For ‘Virginian snake-root’ see SERPENTARY. Snakeweed (_Bistortæ radix_) is the root of _Polygonum Bistorta_ (Linn.).

=SNIPE.= The _Scolopax Gallinago_, a well-known bird indigenous to this country. It is fine-flavoured, but rather indigestible.

=SNOW, Foreign Bodies in.= M. Bondier[170] having lately made an examination of snow, records that of the solid matters floating in the air and retained in the snow, the most abundant was found to be soot; next some cells of _Protococcus virictis_, and spores and filaments of other cryptograms; then granules of starch and cells and fibres of various plants. Epithelial cells and hairs of animals were also present, as well as fibres of wool and silk. These last, being dyed, indicated the presence of man, as did also the fibres of hemp, cotton, and indigo. The amount of foreign matter was greatest in the snow collected at the lowest levels, especially in the vicinity of human habitations and of woods, which are both fertile sources of floating particles. Permanganate of potassium was used to estimate the amount of organic matter dissolved by the filtered snow water.

[Footnote 170: ‘Journ. Ch. Soc.’]

Immediately mixed with the soot were the ferruginous corpuscles observed by Tissandier. These are regarded by the author, in opposition to the opinion of Tissandier, as of terrestrial origin.

=SNUFF.= _Syn._ PULVIS TABACI, L.; TABAC EN POUDRE, Fr. A powder, prepared from tobacco, for the purpose of being sniffed up the nose as a stimulant or intoxicant.

The finer kinds of snuff are made from the soft portions of the best description of manufactured leaf-tobacco, separated from the damaged portion; but the ordinary snuffs of the shops are mostly prepared from the coarser and damaged portions, the mid-ribs, stems, or stalky parts that remain from the manufacture of ‘shag tobacco,’ the dust or powder sifted from the bales, and the fragments that are unfit for other purposes.

_Prep._ The proper material being chosen, and if not in a sufficiently mature state rendered so by further fermentation, they are sufficiently dried by a gentle heat or exposure to the air to admit of being pulverised. This is performed, on the large scale, in a mill, and on the small scale, with a kind of pestle and mortar. During the operation the tobacco is frequently sifted, that it may not be reduced to too fine a powder, and is several times slightly moistened with rose or orange-flower water, or eau d’ange, which are the only liquids fit for the superior kinds of snuff. In preparing the dry snuffs no moisture is used. The scent or other like matters are next added, and, after thorough admixture, the snuff is packed in jars or canisters.

_Adult._ During the grinding of tobacco it is frequently mixed with dark-coloured rotten wood, various English leaves, colouring, and other matter. Ammonia, hellebore, euphorbium, and powdered glass are common additions to snuffs to increase their pungency. We have seen powdered sal ammoniac sent by the hundredweight at one time to a certain celebrated London tobacconist. The moist kinds of snuff are generally drugged with pearlash, for the triple purpose of keeping them damp and increasing their pungency and colour. The dry snuffs, especially ‘Scotch’ and ‘Welsh,’ are commonly adulterated with quicklime, the particles of which may be occasionally distinguished even by the naked eye. This addition causes their biting and desiccating effect on the pituitary membrane. “We were once severely injured by taking snuff which, after our suspicions were awakened, we found to contain a mixture of red lead and umber.” (Cooley.)

The following circumstance related by Dr Garrod[171] in a lecture at King’s College Hospital leads to the inference that the custom of packing snuff in lead is not free from danger. The doctor says:——A gentleman, a resident in India, began to suffer some time since from nervous exhaustion, anæmia, and debility of both extremities; he was a great snuff taker, taking on an average as much as an ounce in the course of a day. He consulted several medical men in India, and they attributed his symptoms to inordinate snuff taking. He, however, continued to take snuff and to get worse, and at last came to England to seek further advice. When Dr Garrod saw him he discovered a blue line on the gums. His suspicions were directed to the snuff, which he found to contain a considerable quantity of lead. To ascertain whether or not the presence of lead in this circumstance was an accidental circumstance, six packets were ordered from the house in Calcutta with which the gentleman had been in the habit of dealing. The snuff was contained in sheet-lead packages, which were all found to contain lead to about the same extent as the first specimen. Dr Garrod exhibited a solution, which he tested in the following way:——Ten grains of snuff were burned in a platinum crucible, and the ash was treated with nitric acid, the crystallised result was dissolved in water with the addition of a small quantity of acetic acid, and then tested with iodide of potassium, which threw down an abundant precipitate of yellow iodide of lead. The leaden packages were labelled ‘best brown rappee,’ and bore the name of a well-known English firm, from which they had been exported to India. The snuff itself was rather moist. Where it adhered to the sides of the case it was dotted with white spots, probably consisting of carbonate of lead, formed by, Dr Garrod suggests, the fermentation of the damp snuff.

[Footnote 171: ‘Lancet.’]

Since Dr Garrod’s attention has been directed to this subject, he has spoken to a medical man recently returned from Calcutta, who told him that he had quite lately met with three cases of lead-poisoning, which, on investigation, were found to be due to the use of snuff.

_Var._ Snuffs are divided into two kinds——DRY SNUFFS, as ‘Scotch,’ ‘Irish,’ ‘Welsh,’ and ‘Spanish snuff,’ ‘Lundyfoot,’ &c.; and MOIST SNUFFS, or RAPPEES, including ‘black’ and ‘brown rappee,’ ‘carrotte,’ ‘Cuba,’ ‘Hardham’s mixture,’ ‘prince’s mixture,’ ‘princeza,’ ‘queen’s snuff,’ &c. The last three also come under the denomination of SCENTED SNUFFS.

The immense variety of snuffs kept in the shops, independently of the above-named conditions, depend for their distinguishing characteristics on the length of the fermentation, the fineness of the powder, the height to which they are dried, and the addition of odorous substances. Tonquin beans, essence of tonquin bean, ambergris, musk, civet, leaves of orchis fusca, root and oil of calamus aromaticus, powder and essence of orris root, and the essences or oils of bergamot, cedra, cloves, lavender, petit grain, neroli, and roses (otto), as well as several others, either alone or compounded, are thus employed. TABAC PARFUMÉE AUX FLEURS is perfumed by putting orange flowers, jasmins, tuberoses, musk roses, or common roses, to the snuff in a close chest or jar, sifting them out after 24 hours, and repeating the treatment with fresh flowers, as necessary. Another way is to lay paper, pricked all over with a large pin, between the flowers and the snuff.

MACOUBA SNUFF is imitated by moistening the tobacco with a mixture of treacle and water, and allowing it to ferment well.

SPANISH SNUFF is made from unsifted ‘Havannah snuff,’ reduced by adding ground Spanish nutshells, sprinkling the mixture with treacle water, and allowing it to sweat for some days before packing.

YELLOW SNUFF is prepared from ordinary pale snuff moistened with a mixture of yellow ochre diffused in water, to which a few spoonfuls of thin mucilage have been added; when dry, the colour that does not adhere to the snuff is separated with a fine sieve.

RED SNUFF. As last, but using red ochre.

=Snuff, Asarabac′ca.= _Syn._ CEPHALIC SNUFF, COMPOUND POWDER OF ASARABACCA; PULVIS ASARI COMPOSITUS, L. _Prep._ 1. (Ph. D. 1826.) Asarabacca leaves, 1 oz.; lavender flowers, 1 dr. (both dried); mix and powder them.

2. (Ph. E. 1817.) Asarabacca leaves, 3 dr.; leaves of marjoram and flowers of lavender, of each 1 dr.; as before. Both are used as errhines in headaches and ophthalmia. See SNUFF, CEPHALIC, ASARABACCA, &c.

=Snuff, Cephal′ic.= _Prep._ 1. From asarabacca leaves and Lundyfoot snuff, of each 2 oz.; lavender flowers, 1/4 oz.; essence of bergamotte and oil of cloves, of each 2 or 3 drops; mixed and ground to a powder, the perfume being added last.

2. (Boeli’s.) From tobacco or pure snuff and valerian root, of each 1/2 oz.; reduced to powder, and scented with the oils of lavender and marjoram, of each 5 or 6 drops.

_Obs._ The first formula is an excellent one; and the product is very useful in nervous headaches, dimness of sight, &c. See SNUFF, ASARABACCA (_above_).

=Snuff, Eye.= _Prep._ From finely levigated tribasic sulphate of mercury (‘Turpeth mineral’), 1/2 dr.; pure dry Scotch or Lundyfoot snuff, 1 oz.; triturate them well together. A pinch of this, occasionally, has been recommended in inflammation of the eyes, dimness of sight, headache, polypus, &c.; but it should be used with caution, and not too often.

=SOAP.= _Syn._ SAPO, L.; SAVON, Fr. SPANISH, CASTILE, or HARD SOAP, made with olive oil and soda (SAPO, SAPO EX OLIVÆ OLEO ET SODÂ CONFECTUS——Ph. L.; SAPO DURUS——B. P., Ph. E., & D.), and SOFT SOAP, made with olive oil and potash (SAPO MOLLIS——B. P., Ph. L., & E., SAPO EX OLIVÆ OLEO ET POTASSÂ CONFECTUS——Ph. L.), are the only kinds directed to be employed in medicine. The former is intended whenever ‘soap’ is ordered, and is the one which is principally employed internally; the latter is used in ointments, &c., and in some of the officinal pills.

_Prep._ The fatty or oleaginous matter is boiled with a weak alkaline lye (soap-lye) rendered caustic by quicklime, and portions of stronger lye are added from time to time, the ebullition being still continued, until these substances, reacting on each other, combine to form a tenacious compound, which begins to separate from the water; to promote this separation and the granulation of the newly-formed soap, some common salt is generally added, and the fire being withdrawn, the contents of the boiler are allowed to repose for some hours, in order that the soap may collect into one stratum, and solidify; when this happens it is put into wooden frames or moulds, and when it has become stiff enough to be handled it is cut into bars or pieces, and exposed to the air, in a warm situation, to further harden and to dry.

In the print works of Alsace, where an immense quantity of egg albumen is consumed, there collect, as a necessary result, enormous quantities of the yolks of egg. Amongst other purposes to which these are applied that of soap-making is one. According to Kingzett, the olein is not the only ingredient of the yolk which reacts upon the soda or potash, and thus produces soap; but the yolk also contains another body, which, absorbing water under the influence of the bases, splits up into oleic and margaric acids.

“Besides the olein contained in the free state, there is,” says Mr Kingzett, “present a body called _lecithine_ of the formula C_{42}H_{84}NPO_{9}.” Gobloy, Diakonow, Strecker, Thudicum, and Kingzett have studied this substance, and express its chemolysis as follows:——

Lecithine. Water. Glycero-phosphoric
acid.
C_{42}H_{84}NPO_{9} - 3H_{2}O = C_{3}H_{9}PO_{6}

Choline. Oleic acid. Palmitic
acid.
+ C_{5}H_{15}NO_{2} + C_{18}H_{34}O_{2} + C_{16}H_{32}O_{2}.

That is to say, bases have the power, by abstracting water, to split up _lecithine_ into, among other products, oleic and palmitic acid; so that when eggs are used for soap-making this process actually occurs, the soda or potash employed being sufficient to effect the necessary decomposition, and the resulting soap being, therefore, the product from not only the olein, but from the fatty acids so formed.

Tessie du Mothay has proposed a method for the recovery of potash, soda, &c., from soap water, which is as follows:——He decomposes the soap water by calcium, barium, or magnesium carbonate, and then passes carbonic acid through the liquid. The bicarbonate form precipitates organic matter and other impurities, and these settle down. The solution is then evaporated or treated with baryta water, which precipitates the last portion of foreign matters, and leaves a solution of caustic alkali. At a particular stage of the process an acid is used in order to hasten the separation of the resinous substances, and, in certain cases, of the sulphides of sodium and calcium, or barium and calcium and ferric oxide, and then passes carbonic acid into the liquid. The precipitated metallic substances carry down with them the humus-like substances present.

_Var._ The principal varieties of soap found in commerce are:——

ALMOND SOAP (SAPO AMYGDALINUS), made from almond oil and caustic soda, and chiefly used for the toilet.

The P. Codex gives the following formula for its preparation:——Solution of caustic soda (1·334), by weight, 10 oz.; oil of almonds, by weight, 21 oz.; add the lye to the oil in small portions, stirring frequently; leave the mixture for some days at a temperature of from 64° to 68° Fahr., stirring occasionally, and when it has acquired the consistence of a soft paste, put it into moulds until sufficiently solidified. It should be exposed to the air for one or two months before it is used.

ANIMAL SOAP. SAPO ANIMALIS, CURD SOAP (B. P.). A soap made with soda and a purified animal fat consisting principally of stearin (P. Cod.). Put 5 parts of beef marrow with 10 parts of water into a porcelain or silver basin, heat, and when melted add by portions, with constant stirring, 2-1/2 parts of liquor sodæ (1·33); when saponified, add 1 part of salt; stir, remove the soap from the surface, drain it, melt it with a gentle heat, and pour it into moulds.

CASTILE SOAP, SPANISH S., MARSEILLES S.; SAPO CASTILIENSIS, SAPO HISPANICUS. An olive-oil soda soap, kept both in the white and marbled state. The former is said to be the purest, the latter the strongest.

CURD SOAP, made with tallow (chiefly) and soda (see _above_).

MEDICATED SOAPS, containing various active ingredients. The chief of these are noticed _below_.

MOTTLED SOAP, made with refuse kitchen-stuff, &c.

SOFT SOAP (of commerce), made with whale, seal, or cod oil, tallow, and caustic potash.

N. Gräger[172] gives the following method for the easy determination of the fat and alkali in soft (potash) soaps:——25 to 50 grammes of soap are dissolved in 150 c.c. of water by aid of heat, cooled, and mixed with an excess of salt, so that a soda-soap separates out; the latter is washed on a paper filter with a saturated solution of salt. In the filtrate the free alkali is estimated by a normal acid. The precipitate is decomposed by warming with excess of normal acid, and the quantity of acid neutralised by the combined alkali, determined by a standard soda solution. The cake of fat which separates in the last operation, is dried and weighed after adding to it, while melted, a known weight of stearin or paraffin to give it hardness.

[Footnote 172: ‘Dingler’s Journal’ (‘Journ. of Chem. Soc.,’ vol. ix, new]

TOILET SOAPS, prepared from any of the preceding varieties, and variously coloured and scented. Formulæ are given _below_.

YELLOW SOAP, RESIN SOAP, made with tallow, resin, and caustic soda. Soluble glass is now largely employed in place of resin.

Soaps are also divided into SOFT or POTASH SOAPS, and HARD or SODA SOAPS.

_Assay._ 1. For the WATER. A piece, fairly taken from the sample, and weighing 100 gr., is reduced to thin shavings, which are dried by the heat of boiling water, until they cease to lose weight. The loss indicates the proportion of free water. This should not exceed 35% for ordinary curd and mottled soap, 45% for yellow soap, and about 15% to 16% for Castile soap.

2. For the ALKALI. 100 gr. of the soap are dissolved in 4 or 5 fl. oz. of boiling water, and the solution tested by the common method of alkalimetry. Curd and yellow soap usually contain from 6% to 7%, mottled soap from 7% to 8%, and Castile soap 8% to 9% of soda.

3. For the OIL or FAT. The solution tested for alkali (see No. 2) is heated, and then allowed to cool slowly; when cold the floating fatty matter is removed, freed from water, and weighed. When the fat or oil has little consistence, 100 gr. of pure white wax is added to the soap solution before heating it. The weight obtained, in grains in the one case, and the excess above 100 gr. in the other, give the proportion of oil or fat present. This, in ordinary mottled soap, should be about 68%; in yellow soap, 65%; in curd soap, 60%; and in Castile soap, 75%.

4. UNSAPONIFIED FATTY MATTER.——_a._ Pure soap is entirely soluble in distilled water and insoluble in saline solution; if a film of fatty matter forms on its solution in the former, after repose, that portion has not been saponified.

_b._ The fat separated from soap (see No. 2), when it has been perfectly saponified, is entirely soluble in alcohol.

5. OTHER IMPURITIES. Pure soap is soluble in rectified spirit, forming a colourless or nearly colourless solution. The undissolved portion, if exceeding 1%, is adulteration.

ANOTHER METHOD OF SOAP ASSAY (M. Moffit). The constituents to be determined in an analysis of soap are alkalies (combined and free), carbonates, fatty acids, resin, glycerin, salts, colouring matters, and water.

Three portions of the finely divided soap are weighed off, containing respectively 10 grams, 20 grams, and 40 grams. Ten grams are digested with alcohol on the water-bath and filtered. The residue containing carbonates and other salts, colouring matter, &c., is dried at 100°, weighed, digested with water, and titrated with normal oxalic acid. Every c.c. of acid used indicates 0·053 Na_{2}CO_{3}.

Regard must be had to a slight precipitate of calcium oxalate. The weight of Na_{2}CO_{3} found is subtracted from the total residue insoluble in alcohol, the difference is the weight of the salts and foreign matters. The filtrate is subjected to a stream of carbonic acid, filtered, and the precipitate dissolved in water and titrated with oxalic acid. Each c.c. of acid indicates 0·031 free soda, or 0·042 free potash. No precipitate shows the absence of free alkalies. The filtrate from the precipitate produced by the carbonic acid is, after the addition of 15 c.c. of water, evaporated to remove the alcohol. The aqueous solution, treated with normal oxalic acid to acid reaction, shows for every c.c. of acid 0·031 soda, or 0·042 potash in combination. Sulphuric acid is then added, and the whole is heated on a water bath with pure beeswax to separate the fatty acids and resin, which are then weighed, the weight of the beeswax being subtracted.

Forty grams of the soap are next dissolved in water and mixed with sulphuric acid, as long as any precipitate is formed. On standing the fatty acids separate, and can be dried and weighed. These fatty acids are digested with a mixture of equal volumes of water and alcohol, till the liquid on cooling ceases to appear milky. The solid layer is again weighed, and the difference between the weight and that obtained above shows the weight of the resin.

The melting point of the acids is next determined. Ten grams are then dissolved in alcohol, and sulphuric acid diluted with alcohol is added, till a precipitate is no longer formed. The liquid is filtered, mixed with barium carbonate, and again filtered. The sweet residue left after evaporation of the alcohol is glycerin. The weights of the carbonates, salts, and foreign matters, free and combined alkalies, fatty acids, resin, and glycerin are added together, and the sum subtracted from 10 grams gives the weight of the water.

See also Soap analysis, ‘Chem. News,’ xxxv, 2. The article is too long to allow of insertion here.

_Uses, &c._ The common uses of soap need not be enumerated. As a medicine it acts as a mild purgative and lithontriptic, and it has been thought by some to be useful in certain affections of the stomach arising from deficiency of bile. _Externally_ it is stimulant and detergent.——_Dose_, 3 to 20 or 30 gr., made into pills, and usually combined with aloes or rhubarb.

_Concluding Remarks._ Prior to the researches of Chevreul, no correct ideas were entertained as to the constitution of soap. It was long known that the fixed oils and fats, in contact with caustic alkaline solutions at a high temperature, undergo the remarkable change which is called saponification; but here the knowledge of the matter stopped. Chevreul discovered that if the soap, so produced, be afterwards decomposed by the addition of an acid, the fat which separates is found to be completely changed in character; to have acquired a strong acid reaction when applied in a melted state to test paper, and to have become soluble with the greatest facility in warm alcohol; in other words——that a new substance, capable of forming salts, and exhibiting all the characteristic properties of an acid, has been generated out of the elements of the neutral fat under the influence of the base. Stearin, when thus treated, yields stearic acid, palmitin gives palmitic acid, olein gives oleic acid, and common animal fat, which is a mixture of several neutral bodies, affords, by saponification by an alkali and subsequent decomposition of the soap, a mixture of the corresponding fatty acids. These bodies are not, however, the only products of saponification; the change is always accompanied by the formation of a very peculiar sweet substance called glycerin, which remains in the mother liquor from which the acidified fat has been separated. The process of saponification itself proceeds with perfect facility, even in a closed vessel; no gas is disengaged; the neutral fat, of whatsoever kind, is simply resolved into an alkaline salt of the fatty acid, which is soap, and into glycerin, a neutral body resembling syrup, and, like that liquid, miscible with water in every proportion.

“When yellow soap is made with the cheaper kinds of fat it will hardly acquire a sufficient degree of firmness or hardness to satisfy the thrifty washerwoman. It melts away too rapidly in hot water, a defect which may be well remedied by the introduction into the soap of a little (1·20th) fused sulphate of soda; and this salt concreting gives the soap a desirable hardness, whilst it improves its colour, and renders it a more desirable article for the washing tub.” (Ure.) This process was patented by Dr Normandy, but soon proved a source of annoyance and molestation to him on the part of the Board of Excise, it being an enormous crime in law to attempt to improve and cheapen soap.

“Soda which contains sulphurets is preferred for making mottled or marble soap, whereas the desulphuretted soda makes the best white curd soap.” “The Barillas always contain a small proportion of potash, to which their peculiar value, in making a less brittle or more plastic hard soap than the factitious sodas, may, with great probability, be ascribed.” (Ure.)

The mottled appearance is usually given, in the London Soap-works, by watering the nearly finished soap with a strong lye of crude soda, by means of a watering can furnished with a rose spout. For ‘Castile soap’ a solution of sulphate of iron is so employed. See SOAPS (Medicated and Toilet).

=Soap, Arsen′ical.= _Syn._ SAPO ARSENICALIS, L. _Prep._ (Bécœurs.) From carbonate of potash, 12 oz.; white arsenic, white soap, and air-slaked lime, of each 4 oz.; powdered camphor, 3/4 oz.; made into a paste with water, q. s. Used to preserve the skins of birds, and other small animals.

=Soap, Black.= _Syn._ SAPO NIGER, S. MOLLIS COMMUNIS, L. A crude soft soap, made of fish oil and potash; but the following mixture is usually sold for it:——Soft soap, 7 lbs.; train oil, 1 lb.; water, 1 gall.; boil to a proper consistence, adding ivory black or powdered charcoal, q. s., to colour. Used by farriers.

=SOAPS (Med′icated).= A few only of these deserve notice here:——

=Soap, Antimo′′nial.= _Syn._ SAPO ANTIMONIALIS, SAPO STIBIATUS, L. _Prep._ (Hamb. Cod. 1845.) Golden sulphuret of antimony, 2 dr.; solution of caustic potassa, 6 dr. (or q. s.); dissolve and triturate the solution with medicated (Castile) soap (in powder), 1-1/2 oz., until the mass assumes a pilular consistence. It should be of a greyish-white colour.

=Soap, Chlorina′ted.= _Syn._ SAPO CALCIS CHLORINATÆ, L.; SAVON ANTISYPHILITIQUE, Fr. _Prep._ From Castile soap (in powder), 11 oz.; chloride of lime (dry and good), 1 oz.; mix, beat them to a mass with rectified spirit, q. s.; (holding in solution) oil of verbena or of ginger grass, 1/4 oz.; lastly, form the mass into flat tablets, and wrap these in thin sheet gutta percha. A most excellent detergent and stimulant soap in various affections, admirably adapted for hospital use, and for removing stains from the skin and rendering it white. It is the most powerful known agent against infection from contagious diseases communicable by contact.

=Soap, Cod-Liver Oil.= _Syn._ SAPO OLEI JECORIS (Deschamps). _Prep._ Cod-liver oil, 2 oz.; caustic soda, 2 dr.; water, 5 dr.; dissolve the soda in the water, and mix it with the oil. An ioduretted soap is made by mixing with the above, 1 dr. of iodide of potassium dissolved in 1 dr. of water.