Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 190

Several machines have recently been invented by which water is frozen in large quant.i.ties by exposure to condensed air in the act of its subsequent expansion. They are worked by either hand or steam power. The refrigerating apparatus invented by Mr Kirk, of the Bathgate Paraffin Works, acts on this principle; and it does its work so efficiently that it produces a cooling effect equivalent to two tons of ice every twenty-four hours, at a very small expenditure of fuel. A small model worked by hand will readily freeze mercury. Kirk's apparatus is used at Bathgate to cause the crystallisation of solid paraffin from the heavy paraffin oils.

Formerly, a machine, acting by the evaporation of ether, was employed for the same purpose.

For the production of an extremely low temperature, such as is required for the liquefaction of some gases, Faraday employed solid carbonic acid mixed with a little ether.

In the production of ice or an extreme degree of cold, by saline mixtures, the salts should be in the crystallised state, and as rich as possible in water, but without being in the least damp. They should also be coa.r.s.ely pulverised at the time of using them, and should not be mixed until immediately before throwing them into the liquid ingredients. The mixture should be made in a thick vessel, well clothed, to prevent the accession of external heat; and the substance to be acted on should be contained in a very thin vessel, so as to expose it more fully to the action of the mixture. On the large scale, a vessel called a 'FREEZING POT' or 'SABOTIeRE' is commonly employed. The following table, though founded on experiments made more than 50 years ago by Mr Walker, gives full and accurate information on the subject of freezing mixtures:--

Table _exhibiting a few of the most useful_ FRIGORIFIC MIXTURES. _Drawn up from actual experiments performed by_ MR WALKER.

+----------------------------------------+------------------------+---------------+ Deg. of cold Ingredients. Thermometer sinks. produced. +----------------------------------------+------------------------+---------------+ Snow or pounded ice 2 parts { From any Chloride of sodium 1 " { temperature. to -5 -- +----------------------------------------{------------------------+---------------+ Snow or pounded ice 5 " { From any Chloride of sodium 2 " { temperature. to -12 -- Sal ammoniac 1 " { +----------------------------------------{------------------------+---------------+ Snow or pounded ice 12 " { From any Chloride of sodium 5 " { temperature to -25 -- Nitrate of ammonia 5 " { +-----------------------------------------------------------------+---------------+ Snow 8 " Hydrochloric From +32 to -27 59 acid (_concentrated_) 5 " +-----------------------------------------------------------------+---------------+ Snow 2 " Crystallised chloride From +32 to -50 82 of calcium 3 " +-----------------------------------------------------------------+---------------+ Sal ammoniac 5 " Nitrate of pota.s.sa 5 " From +50 to +10 40 Water 16 " +-----------------------------------------------------------------+---------------+ Nitrate of ammonia 1 " From +50 to +4 46 Water 1 " +-----------------------------------------------------------------+---------------+ Nitrate of ammonia 1 " Carbonate of soda 1 " From +50 to +7 57 Water 1 " +-----------------------------------------------------------------+---------------+ Phosphate of soda 9 " Nitrate of ammonia 6 " From +50 to -21 71 Diluted nitrous acid[135]4 " +-----------------------------------------------------------------+---------------+ Sulphate of soda 8 " From +50 to 0 50 Hydrochloric acid 5 " +-----------------------------------------------------------------+---------------+ Snow 3 " From 0 to -46 46 Diluted nitrous acid[135]2 " +-----------------------------------------------------------------+---------------+ Snow 2 " Sulphuric acid[136] 1 " From -20 to -60 40 Water 1 " +-----------------------------------------------------------------+---------------+ Snow 1 " Crystallised chloride From 0 to -66 66 of calcium 2 " +-----------------------------------------------------------------+---------------+ Snow 1 " Crystallised chloride From -40 to -73 33 of calcium 3 " +-----------------------------------------------------------------+---------------+ Snow 8 " Sulphuric acid 5 " From -68 to -91 23 Water 5 " +-----------------------------------------------------------------+---------------+

[Footnote 135: Fuming "nitrous acid," 2 parts; water, 1 part; by weight.]

[Footnote 136: Prof. Pfaundler has shown that an acid containing 6619 per cent. of H_{2}SO_{4}, is the most advantageous to employ for this purpose; one part of an acid of this strength with 1097 parts of snow forming a refrigerating mixture which will reduce the temperature to -37 C. (-36 F.). For practical purposes it is suggested an excess of snow would be better, since the refrigerating value of the mixture is thereby largely increased, though the lowest temperature is not obtained. See ICE.]

_Obs._ The materials in the first column are to be cooled, previously to mixing, to the temperature required in the second, by the use of other mixtures.

=REG'ULUS.= A term applied by the alchemists to various metallic matters obtained by fusion; as REGULUS OF ANTIMONY, a.r.s.eNIC, &c. It is now obsolete.

=REL'ISHES.= See SAUCES.

=REMEDIES, FERRUGINOUS.= Rob. Freygang:--

STEEL BRANDY is an ordinary clear brownish brandy, containing a very little bitter matter, like the stomachic bitters of the apothecaries, and mixed with about 1 per cent. of sugar. 10,000 parts contain about 1-1/2 part oxide of iron.

STEEL STOMACHIC BITTERS. This is more aromatic, but otherwise similar to the steel brandy; 10,000 parts contain 2/3 part iron oxide.

STEEL LIQUEUR is a clear, agreeably-tasting liqueur, of the colour and containing much of the juice of raspberries. 10,000 parts contain nearly 1,200 of sugar and only 1 of iron oxide.

STEEL SYRUP--Syrop ferrugineux de Quinquina. A clear slightly violet-coloured, thin, sweet fluid, containing spirit and sugar, of which cinchona bark may be an ingredient, though it is appreciable by neither taste nor tests. It contains 1-1/4 part iron in 10,000 parts.

STEEL BONBONS contain a trace of iron oxide.

The iron present in the above preparations is in the form of citrate.

(Hager.)

=REMIT'TENT.= A term applied to fevers, and other diseases, which exhibit a decided remission in violence during the twenty-four hours, but without entirely leaving the patient, in which they differ from intermittents or agues.

=REN'NET.= _Syn._ RUNNET, PREPARED CALF'S MAW. The fourth or true digesting stomach of the calf, freed from the outer skin, fat, and useless membrane, washed, treated with either brine or dry salt for a few hours, and then hung up to dry. When well prepared, the dried 'vells' somewhat resemble parchment in appearance.

_Uses, &c._ Rennet is employed to curdle milk. A piece of the requisite size is cut off, and soaked for some hours in whey or water, after which the whole is added to the milk for curdling, slightly warmed, and the mixture is slowly heated, if necessary, to about 122 Fahr. In a short time after this temperature has been attained the milk separates into a solid white coagulum (curd), and into a yellowish, translucent liquid (whey). Two square inches from the bottom of a good 'vell' are sufficient for a cheese of 60 lbs. It is the gastric juice of the stomach that operates these changes. The stomachs of all sucking quadrupeds possess the same properties. See CHEESE.

=Rennet, Liquid.= _Syn._ ESSENCE OF RENNET. _Prep._ From fresh rennet (cut small), 12 oz.; common salt, 3 oz.; knead them together, and leave the mixture at rest, in a cool place, for 5 or 6 weeks; then add of water 18 oz.; good rum or proof spirit, 2 oz.; lastly, digest for 24 hours, filter, and colour the liquid with a little burnt sugar.

=Rennet, Liquid.= _Syn._ ESSENCE OF RENNET. Fresh rennet, 12 oz.; salt, 2 oz.; proof spirit, 2 oz.; white wine, a quart; digest for 24 hours and strain. A quart of milk requires 2 or 3 teaspoonfuls. WISLIN directs 10 parts of a calf's stomach; salt, 3 parts. The membrane of the stomach is to be cut with scissors and kneaded with the salt, and with the rennet found in the interior of that organ; the whole left in a cool place in an earthen pot till the cheesy odour is replaced by the proper odour of rennet, which will be in one or two months. Then add 16 parts of water and 1 of spirit. Filter and colour with burnt sugar.

The German Pharmacopia gives the following formula for liquid rennet:--3 parts of the mucous membrane of fresh calf's rennet, macerated for three days in 26 parts of white wine, 1 part of table salt being added.

_Obs._ 2 or 3 teaspoonfuls will curdle a quart of milk. Some persons use white wine instead of water, with simple digestion for a day or two.

=RES'IN.= _Syn._ RESINA, L. This name is applied to many vegetable principles composed of the elements carbon, hydrogen, and oxygen. The resins (RESINae) cannot be very accurately defined, but we may in a general way describe them as substances which are solid at ordinary temperatures, more or less transparent, inflammable, readily fusible, do not volatilise unchanged, become negatively electrified by rubbing; are insoluble in water, but soluble in alcohol; mostly inodorous, and readily incorporated with fatty bodies by fusion. Their sp. gr. varies from 9 to 12.

According to Liebig, they are oxidised essential oils. Common resin, rosin, or colophony, and the sh.e.l.lac of which sealing-wax is made, are familiar examples of these substances. (See _below_.)

=Resin, Black.= _Syn._ ROSIN, BLACK R., COLOPHONY; RESINA NIGRA, COLOPHONIA, L. What remains of turpentine after the oil has been distilled. When this substance, whilst still fluid, is agitated with about 1-8th part of water, it forms the yellow resin of pharmacy. Used for violin bows, dark-coloured ointments, varnishes, &c.

=Resin, Yel'low.= _Syn._ YELLOW ROSIN, WHITE R.; RESINA FLAVA, RESINA (Ph. L.), La. Detergent. Used in ointments, plasters, &c. (See _above_.)

=RES'INOIDS.= _Syn._ RESINOUS EXTRACTS, CONCENTRATED E.; EXTRACTA RESINA, L. Under this head, the so-called 'Eclectics,' who form a numerous cla.s.s among American physicians, place their most important 'concentrated remedies.' "Viewed as pharmaceutical preparations eligible for use in medicine, though not purified so as to rank as distinctive proximate principles, these are very appropriately named 'resinous extracts,' or 'resins.' The term 'resinoid,' so commonly used, is less appropriate to the cla.s.s, implying, as it does, a resemblance to resins, while all of these are either resins, oleo-resins, or more or less mixed proximate principles possessing no real resemblance to the cla.s.s of resins."

(Parrish.) Most of them are prepared from plants indigenous to North America, by precipitating a strong alcoholic tincture with water. They are all brought to the condition of powder, those which are naturally soft and oily being mixed with a sufficient quant.i.ty of sugar of milk, or other dry material. One of these eclectic remedies has been introduced into regular practice. See PODOPHYLLIN.

=RESIN, or ROSIN OIL.= This is a product of the dry distillation of resin.

The apparatus used consists of an iron pot, a head piece, a condensing arrangement, and a receiver.

In distilling the resin, a bright oil first comes over with water. As soon as a cessation in the flow of the distillate occurs the receiver is changed, and the heat is further raised, when a red-coloured and heavy rosin oil comes over. The black residue remaining in the pot is used as pitch. The light oil, called 'pinoline,' is rectified, and the acetic acid water pa.s.sing over with it is saturated with calcium hydrate, filtered and evaporated to dryness; and the calcium acetate obtained is employed in the manufacture of acetic acid. The rosin oil, obtained after the light oil has pa.s.sed over, has a dark violet-blue colour, and is called 'blue rosin oil.' The red oil is boiled for a day with water, the evaporated water being returned to the vessel; next day the water is drawn off, and the remaining rosin oil is saponified with caustic soda lye of 36 Baume, and the resulting solid ma.s.s is distilled so long as oil pa.s.ses over.

The product obtained is 'rectified rosin oil,' which is allowed to stand in iron vessels, protected by a thin layer of gypsum, whereby after a few weeks a perfectly clear oil is obtained free from water. The oil of first quality is obtained by a repet.i.tion of the foregoing operation upon the once rectified oil. The residues of both operations are melted up with the pitch.[137]

[Footnote 137: Dingler's 'Polytech. Journ.,' ccvi, 246 ('Journ. Chem.

Soc.,' new series, vol. xi, 304).]

Rosin oil is employed in the manufacture of axle grease, the oil being previously converted into a soap by heating with slaked lime.

=RESOLV'ENTS.= _Syn._ DISCUTIENTS; RESOLVENTIA, L. Substances or agents which discuss or resolve inflammatory and other tumours. See DIGESTIVES.

=RESPIRA'TION.= The peculiar function by which the blood is submitted to the action of the air, for the purpose of removing carbonic acid, and restoring its vitality by the absorption of atmospheric oxygen.

The air expired from the lungs is found to have undergone a most remarkable change. It is now loaded with aqueous vapour, whilst a considerable portion of its oxygen has disappeared, and its place is supplied by about a like volume of carbonic acid. It is no longer capable of supporting animal life, and even a lighted taper plunged into it is immediately extinguished. In the mean time the 'venous blood' which entered the lungs from the right chambers of the heart has lost its dingy hue, and has acquired the rich florid colour which is characteristic of 'arterial blood.' In this state it is returned to the left chambers of the heart, and is propelled by that organ to every part of the body, from which it pa.s.ses by the capillaries to the veins, and by these again to the heart and lungs, to undergo the same changes and circulation as before.

The carbon and hydrogen of the blood, ultimately derived from the food, are, in this course, gradually converted into carbonic acid and water by a species of slow combustion; but how these changes are effected is not definitely ascertained.

The lungs, as is well known, receive the atmospheric air through the trachea or windpipe. At the root of the neck this divides into two branches, called bronchi, and each bronchus, upon entering its respective lung, divides into an infinity of small tubes. The latter terminate in small pouches, called the air-cells, and a number of these little air-cells communicate together at the extremity of each small tube. The number of air-cells in the two lungs has been estimated at 1,744,000,000, and the extent of the membrane which lines the cells and tubes together at 1500 square feet. (Dr Addison.) Under ordinary circ.u.mstances, from 22 to 43 cubic inches of air are thrown out at each expiration; but, by a forced effort, 50 or 60 inches are ordinarily expelled. The number of respirations per minute in health, when the individual is tranquil and undisturbed, is about 15. Exercise increases this number. See FOOD, NUTRITION, &c.

=Respiration, Artificial.= Various means have been adopted for this purpose, among which blowing air into the lungs is, perhaps, that generally adopted. A better, and, in general, a much more efficient method, is as follows:--Powerful but not violent pressure is made upon the sides of the chest and upon the abdomen at the same time, by which the cavity of the thorax is diminished, and the air contained in the lungs is expelled; the compression is then suddenly withdrawn, when the elasticity of the ribs causes them to resume their old expanded positions; the chest is again enlarged, a partial vacuum is formed, and air rushes into the lungs, to be again expelled by pressure upon the ribs and abdomen as before. By this means artificial respiration may be kept up for a great length of time, without the use of bellows, or any other apparatus. The chief principle of Dr Marshall Hall's so-called 'ready method' is the postural performance of artificial respiration. The patient is first placed gently on the face, and then turned on the side; then on the face again, alternately; these measures being repeated deliberately, efficiently, and perseveringly, fifteen times in the minute. When the p.r.o.ne position is resumed, equable, but efficient, pressure is applied along the spine; this pressure is removed immediately before rotation on the side.

The 'Silvester method,' invented by Dr Henry Silvester, is now acknowledged to be far more effective than Dr Hall's method, and is adopted by the Royal Humane Society for the restoration of the apparently drowned. It consists in laying the patient on the back, slightly raising the head and shoulders, drawing the tongue forwards, and keeping it so by pa.s.sing an elastic band over it and under the chin. The arms are then grasped just above the elbows, and drawn gently upwards until they meet above the head (this is for the purpose of drawing air into the lungs), keeping the arms in that position for two seconds. The patient's arms are then turned down, and pressed gently and firmly for two seconds against the sides of the chest (this is for the purpose of pressing the air out of the lungs). Artificial breathing is thus carried on. These efforts are repeated fifteen times in a minute, until a spontaneous effort to respire is perceived. During the employment of these means the nostrils are excited with snuff or smelling salts, or the throat is tickled with a feather. After natural breathing has been restored, warmth and circulation are induced by wrapping the body in hot blankets, applying bottles or bladders of hot water, heated bricks, &c., to the pit of the stomach, the armpits, between the thighs, and to the soles of the feet, and by rubbing the limbs upwards firmly and energetically.

In the 'Landw. Versuchs Stat.' (xviii, 81-169)[138] Rudolph Pott has recorded a series of interesting experiments inst.i.tuted with the object of determining the comparative quant.i.ties of carbonic acid excreted by respiration and perspiration in different species of animals in equal intervals of time; together with some experiments on the excretion of carbonic acid by the same animals under different physiological conditions.

[Footnote 138: 'Journ. Chem. Soc.,' 1876, vol. i, p. 721.]

The author states that in his researches he used an air tight box, with gla.s.s sides, in which the animal is placed, and through which the air can be drawn at any rate required by means of an aspirator.

The air before entering the gla.s.s chamber pa.s.ses over caustic potash and through baryta water; after leaving the chamber it pa.s.ses through three flasks containing known quant.i.ties of baryta water.

In the first part of this paper the author estimates the amount of carbonic acid excreted by different animals during the s.p.a.ce of six hours, and under otherwise similar circ.u.mstances. The following are the most important conclusions he arrives at:--

1. The greatest quant.i.ty of carbonic acid in proportion to their weight is given off by birds. Mammals are the next in order. Insects exhale less than either of these.

2. Worms, amphibia, fishes, and snails form another group which excrete much less carbonic acid. Of these worms exhale the most and snails the least.

3. Those animals of the second group, which live in water, give off the greatest part of their carbonic acid to the air, and only a much smaller portion to the surrounding water.