Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 25

=Liniment, White's.= The old name for spermaceti ointment.

=Liniment, White.= _Syn._ LINIMENTUM ALb.u.m. _Prep._ Rectified oil of turpentine, 2 oz.; solution of ammonia, 2 oz.; soap liniment, 3 oz.; spirit of rosemary, 1 oz. Mix in the above order, and gradually add with continual agitation, distilled vinegar, 8 oz. For chapped hands.

=Liniment, Wilkinson's.= _Prep._ (Phbus.) Prepared chalk, 20 gr.; sulphur, lard, and tar, of each 1/2 oz.; mix, and add of Boyle's fuming liquor, 10 or 15 drops. In certain chronic skin diseases, neuralgia, &c.

=Linimentum Aconiti.= (B. P.) Aconite root, in powder, 20; camphor, 1; rectified spirit, to percolate, 30. Moisten the root for 3 days, then pack in a percolator, and pour sufficient rectified spirit upon it to produce with the camphor 20.

Strength, 1 in 1. Applied with a camel-hair pencil, alone or mixed in equal proportions, with a soap liniment or compound camphor liniment, and rubbed on the part. Seven parts of this, and 1 part of chloroformum belladonna, and sprinkled thinly on impermeable piline, is the best application for neuralgia or lumbago.

=Linimentum Pota.s.sii Iodidi c.u.m Sapone.= (B. P.) Hard soap, in powder, 1-1/2; iodide of pota.s.sium, 1-1/2; glycerin, 1; oil of lemon, 1/8; water, 1. Dissolve the soap in 7 of water by heat of a water bath; dissolve the iodide of pota.s.sium in the remainder of the water, and mix by trituration the two solutions, and when cold add the oil of lemon, and mix thoroughly.

=LINOLEIC ACID.= C_{16}H_{28}O_{2}. This may be obtained by saponifying linseed oil. It is a liquid acid, and rapidly oxidizes when exposed to the air, becoming converted into oxylinoleic acid, which is incapable of solidification even at low temperatures.

=LIN'SEED.= _Syn._ FLAX SEED; LINI SEMINA, L. The seed of _Linum usitatissimum_ (Linn.), or common flax. (Ph. L.) Oily, emollient, demulcent, and nutritive. Ground to powder (linseed meal; farina lini), it is used for poultices. The cake left after expressing the oil (linseed cake) contains, when of average quality, in 100 parts, moisture, 1270; oil, 1132; alb.u.menoids, 2821; mucilage, &c., 2942; indigestible fibre, 1246; ash, 589. It is used for feeding cattle. Under the form of tea or infusion it is used as a diluent, and to allay irritation in bronchial, urinary, and other like affections. See INFUSION OF LINSEED.

=LINSEED CAKE.= See LINSEED.

=LINT.= _Syn._ LINTEUM, L. White linen-cloth, sc.r.a.ped by hand or machinery, so as to render it soft and woolly. The hand-made lint is now little used; it was prepared from pieces of old linen-cloth. The machine-made lint is prepared from a fabric woven on purpose. A lint made from cotton (cotton-lint) is now largely manufactured; it is much inferior to the true lint, being a bad conductor of heat. Lint is used for dressing ulcers, either alone or smeared with some suitable ointment or cerate.

=Lint, Medica'ted.= _Syn._ LINTEUM MEDICATUM, L. NIGRUM, L. INFERNALE, L.

_Prep._ 1. Nitrate of silver, 20 to 30 gr.; distilled water, 1 fl. oz.; dissolve, saturate dry lint, 1/2 oz., with the solution, and expose it in a saucer or capsule to the light and air, until it has become black and dry.

2. Nitrate of silver and nitrate of copper, of each 1/2 dr.; lint, 1 oz.; water, 1-1/2 fl. oz.; as the last. Used to dress old and indolent ulcers.

=LIP SALVE.= See SALVE.

=LIQUA'TION.= The process of sweating out by heat the more fusible metals of an alloy. Metallurgists avail themselves of this method in a.s.saying and refining the precious metals and procuring antimony and some other metals from their ores.

=LIQUEFA"CIENTS.= _Syn._ RESOLVENTS; LIQUEFACIENTIA, RESOLVENTIA, L. In _pharmacy_, substances or agents which promote secretion and exhalation, soften and loosen textures, and promote the absorption or removal of enlargements, indurations, &c. To this cla.s.s belong the alkalies, antimony, bromine, chlorine, iodine, mercury, sulphur, &c., and their preparations.

=LIQUEFAC'TION.= The a.s.sumption of the liquid form. It is usually applied to the conversion of a solid into the liquid state, which may arise from increase of temperature (fusion), absorption of water from the atmosphere (deliquescence), or the action of a body already fluid (solution).

=Liquefaction of Gases.= Under the combined influence of pressure and cold, all the gases may be liquefied, and some even solidified. The first satisfactory experiments in this direction were made by Faraday, who succeeded in reducing to the liquid condition eight bodies which had hitherto been regarded as permanent gases, namely, ammonia, carbonic anhydride, chlorine, cyanogen, hydrochloric acid, nitrous oxide, sulphuretted hydrogen, and sulphurous anhydride. His method of proceeding was very simple:--the materials were sealed up in a strong, narrow, gla.s.s tube, bent so as to form an obtuse angle, together with a little 'pressure gauge,' consisting of a slender tube closed at one end, and having within it, near the open extremity, a globule of mercury. The gas, being disengaged by the application of heat or otherwise, acc.u.mulated in the tube, and by its own pressure brought about liquefaction. The force required for this purpose was judged of by the diminution of volume of the air in the pressure gauge. By employing powerful condensing syringes, and an extremely low temperature, Faraday subsequently succeeded in liquefying olefiant gas, hydriodic and hydrobromic acids, phosphuretted hydrogen, and the gaseous fluorides of silicon and boron. He failed, however, with oxygen, hydrogen, nitrogen, nitric oxide, carbonic oxide, and coal-gas, all of which refused to liquefy at the temperature of -166 Fahr., while subjected to pressures varying in different cases from 27 to 58 atmospheres.

Within the last year, however, viz. toward the end of 1877, these hitherto refractory gases have been reduced to the liquid, and, in the case of hydrogen, to the solid state. These results have been accomplished by subjecting the gases to a pressure considerably greater than that employed by Faraday, combined with the expedient of the sudden removal of this pressure, whereby the escaping gas (previously enormously reduced in temperature) in the act of expansion robs the remainder of so much of its heat as to leave it in the fluid condition.

The liquefaction of oxygen was accomplished independently by M. Cailletet, of Paris, and M. Pictet, of Geneva; the French chemist having effected it on December 2nd, 1877, and the Swiss one on the 22nd of the same month.

Simultaneously with Cailletet's announcement of the liquefaction of oxygen, that of carbonic oxide was made by the same chemist; who, about three weeks after at a meeting in the Paris Academy of Sciences, stated that he had also reduced hydrogen, nitrogen, and atmospheric air to the fluid state.

In the previous November he had been equally successful in converting gaseous nitric oxide into a liquid.

M. Cailletet, in a communication to the Paris Academy of Sciences, read by M. Dumas at a meeting of that body on 24th December, 1877, thus describes the process by which he liquefied the gases oxygen and carbonic oxide.

"If oxygen or pure carbonic oxide be enclosed in a tube such as I have before described, and placed in an apparatus for compression like that which has already been worked before the Academy,[17] and the gas be then lowered in temperature to 29 C., by means of sulphurous acid and at a pressure of about 300 atmospheres, the two gases preserve their gaseous state.

[Footnote 17: This apparatus, which consists of a hollow steel cylinder, to which is attached a strong gla.s.s tube, is described in the 'Comptes Rendus,' tome 85, p. 851. The gas is forced into it by means of a hydraulic pump with the intervention of a cus.h.i.+on of mercury.]

"But if they are allowed to suddenly expand, this expansion, according to the formula of Poisson, reducing them to a temperature at least 200 C.

below their initial temperature, causes them immediately to a.s.sume the appearance of an intense fog, which is caused by the liquefaction and perhaps by the solidification of the oxygen or carbonic acid.

"The same phenomenon is also observed, upon the expansion of carbonic acid, and of protoxide and binoxide of nitrogen, when under strong pressure.

"This fog is produced with oxygen, even when the gas is at the ordinary pressure, provided time is allowed for it to part with the heat it acquires in the mere act of compression.

"This I demonstrated by experiments performed on Sunday, the 16th December, at the Chemical Laboratory of the Ecole Normale Superieure, before a certain number of savants and professors, amongst whom were some members of the Academy of Sciences. I had hoped to find in Paris, together with the materials necessary for the production of a high degree of cold (protoxide of nitrogen or liquid carbonic acid), a pump capable of supplying the place of my compression apparatus at Chatillon-sur-Seine.

Unfortunately a pump well fixed and suited to this sort of experiment could not be found in Paris, and I was obliged to send to Chatillon-sur-Seine for the refrigerating substances for collecting the condensed matters on the walls of the tube.

"To know whether oxygen and carbonic oxide are in a liquid or a solid state in the fog would necessitate an optical experiment more easy to imagine than to accomplish, because of the form and the thickness of the tubes containing them. Furthermore, chemical reactions will a.s.sure me that the oxygen is not transformed into ozone in the act of compression. I shall reserve the study of all these questions till the apparatus I am now having made is complete.

"Under the same conditions of temperature and pressure, even the most rapid expansion of pure hydrogen gives no trace of nebulous matter. There remains for me only nitrogen to study, the small solubility of which in water induces me to believe that it will prove very refractory to all change of condition."[18]

[Footnote 18: 'Comptes Rendus,' tome 5, p. 1213.]

[Ill.u.s.tration]

M. Pictet's process for liquefying oxygen, although differing in the method of working, is similar in principle to that of M. Cailletet. His paper, which was read at the same sitting of the Academy as M.

Cailletet's, thus describes it:--

"A and B, in the accompanying figure, are two double section and force pumps, coupled together on the compound system, one causing a vacuum in the other in such a manner as to obtain the greatest possible difference between the pressures of suction and forcing."

The pumps act on anhydrous sulphurous acid contained in the cylindrical receiver c. The pressure in this receiver is such that the sulphurous acid is evaporated from it at a temperature of 65 C. below zero.

The sulphurous acid is forced by the pumps into a condenser, d, cooled by a current of cold water; here it liquefies at the temperature of 25 above zero, and at a pressure of about 2-3/4 atmospheres.

The sulphurous acid returns to the receiver C as it liquefies by the little tube _d_.

E and F are two pumps resembling the preceding, and coupled in the same manner. They act upon carbonic acid contained in a cylindrical receiver H.

The temperature in this latter receiver is such that the carbonic acid evaporates from it at a temperature of 140 C. below zero.

The carbonic acid forced on by the pumps is driven into the condenser K, enclosed in the sulphurous acid receiver C, which has a temperature of 65 below zero; the carbonic acid here becomes liquefied at a pressure of five atmospheres.

The carbonic acid, in proportion as it liquefies, returns to the receptacle H by the small tube _k_.

L is a retort of wrought iron, sufficiently thick to resist a pressure of 500 atmospheres. It contains chlorate of pota.s.sium, and is heated in such a manner as to give off pure oxygen. It communicates by a tubulure with an inclined tube, M, made of very thick gla.s.s, one metre in length, which is enveloped by the receiver, H, containing carbonic acid at the temperature of 140 below zero.

A tap, N, situated upon the tubulure of the retort, permits of the opening of an orifice, P, which leads into the surrounding air.

After the four pumps have been worked for several hours by means of a steam engine of 15-horse power, and when all the oxygen has been disengaged, the pressure in the gla.s.s tube is 320 atmospheres, and the temperature at 140 below zero.

Upon suddenly opening the orifice, P, the oxygen escapes with violence, producing, in doing so, so considerable an expansion and absorption of heat as to cause a liquefied portion to appear in the gla.s.s tube, and to spirt out from the orifice when the apparatus is sloped.

It ought to be stated that the quant.i.ty of liquefied oxygen contained in the tube one metre long and 001 m. in internal diameter, occupied about a third of its length, and issued from the orifice P in the form of a liquid jet.

In a communication to M. Dumas, received two days after the above sitting, M. Pictet described his experiments more fully, prefacing the account by the following very interesting remarks:--"The end to which I have been tending for the last 3 years has been to seek to demonstrate experimentally that molecular cohesion is a general property of bodies without exception.

"If the permanent gases cannot be liquefied, it must be concluded that their const.i.tuent particles do not attract each other, and are therefore independent of this law.