Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 109

_b._ From binoxide of manganese, as the last. 1 oz. of the pure binoxide yields 44 gr., or 128 cubic inches, of oxygen (Liebig); 1 lb. of good commercial binoxide yields from 1500 to 1600 cubic inches, or from 5 to 6 galls.

_c._ M. Boussingault has reinvestigated a process, long known, although not usefully applied, by which pure oxygen gas may be obtained from the atmosphere at a trifling cost, so as to enable it to be collected in unlimited quant.i.ties and preserved in gasometers, like coal-gas, for application in the arts, manufactures, and sanitation. This process depends upon a peculiar property possessed by the earth baryta, of absorbing atmospheric oxygen at one temperature and evolving it at another; or rather, the ready conversion of hydrate of barium into peroxide of barium by a current of atmospheric air at a dull red heat, and the decomposition of this peroxide, by steam, at a lower temperature, even at 212 Fahr., with reproduction of hydrate of barium, the process being in reality a continuous one. The baryta is mixed with a portion of hydrate of calcium or of magnesium, and the mixture being placed in an appropriate earthen tube heated to dull redness, is oxidised by pa.s.sing a current of dry atmospheric air over it. As soon as the oxidation is complete, the tube is connected with the gas-holder, and a jet of steam allowed to act upon it; this reconverts the peroxide of barium into hydrate of barium, the excess of oxygen being given off and collected in the gas-holder. The baryta is then again oxidised by a fresh current of air and deoxidized by steam, and the whole process is repeated as frequently as required. One ton of baryta, thus treated, is capable of yielding 2500 cubic feet of pure oxygen every 24 hours; and this, as it does not waste or lose its properties, at the mere cost of the fuel and labour required in the process.

_d._ From ferrate of pota.s.sium, prepared on the large scale. When exposed to moisture or thrown into water, pure oxygen is evolved. This method has been successfully adopted to maintain the air of diving-bells, and of other confined s.p.a.ces, in a state fit for respiration.

_e._ The decomposition of sulphuric acid has been recommended by MM.

Deville and Debray as a means whereby large quant.i.ties of oxygen gas may be obtained at a low price. Into a tubulated retort are put fragments of fire brick, and upon these, when raised to a full red heat, sulphuric acid is made to fall drop by drop, by pa.s.sing through an iron tube, which pa.s.ses through and is luted to the tubulure. The tube reaches to the bottom of the retort, and the acid is poured into it through a bent funnel. The sulphuric acid becomes decomposed into sulphurous anhydride, oxygen, and water. The volatilised products are sent through a spiral condenser, by which the water and any undecomposed acid become liquefied; whilst the sulphurous acid is removed by subsequent was.h.i.+ng with water, and oxygen is collected in the usual manner.

_f._ A process for obtaining oxygen on a large scale, and which has been made the subject of a patent in this country, has been devised by MM.

Marechal and Tessie du Mothay. It consists in heating in a current of steam the manganates, permanganates, chromates and ferrates of the alkalies and alkaline earths, and regenerating the residue by pa.s.sing air over it at a red heat.

_g._ Mallet procures oxygen in large quant.i.ties as follows:--He puts into retorts revolving on horizontal axes, a mixture of cuprous chloride, and kaolin or sand. He moistens this with water, heats it to 100 C., and pa.s.ses air through the retorts for some hours. His oxygen he obtains from heating the resulting cupric oxychloride to about 400 C.; the aqua residual cuprous chloride becomes converted into oxychloride on cooling 100 kilograms of cuprous chloride, after conversion into oxychloride, about 3 cubic metres of oxygen.

7. OXYGEN GAS AT THE ORDINARY TEMPERATURE. Boettger states that when a mixture is made of equal weights of the peroxides of lead and barium, and dilute HNO_{3} of a strength of 9 Baume is poured thereon, a current of pure O, free from ozone and antozone, is given off abundantly. This mixture of the two peroxides may be kept dry in a stoppered bottle for any length of time. Boettger also prepares pure oxygen, free from ozone, by submitting permanganate of pota.s.sium to a gentle heat.

8. Fleitman[80] has found that when chloride of lime in solution is heated with a small quant.i.ty of freshly prepared peroxide of cobalt, it is completely resolved into chloride of calcium and oxygen. A concentrated solution consisting of 35 per cent. of chloride of lime, which must be previously filtered to prevent frothing, yields when heated with 1/10th to 1 per cent. of peroxide of cobalt, a volume of oxygen from 25 to 30 times as great as that of the liquid, and always rather more than the calculated quant.i.ty, probably in consequence of the absorption of oxygen from the air. The remaining peroxide may always be employed again. A like result follows if, instead of the peroxide, an ordinary salt of cobalt in small quant.i.ty be used. Fleitman seeks to explain the reaction on the supposition that there are several peroxides of cobalt, and that the effects produced depend upon the alternate formation and partial reduction of a higher oxide; or on the formation of a cobaltic and a percobaltic hypochlorite, which is subsequently decomposed into cobaltous chloride and oxygen.

[Footnote 80: Watts.]

_Prop._ Oxygen gas is colourless, tasteless, inodorous, and incombustible; the sp. gr. is 1057 (Dumas; 11026--Berzelius & Dulong; 1111--Thomson); 100 cubic inches at 60 Fahr., and 36 inches of the barometer, weigh 3429 gr. (Dumas; 34109 gr.--Berz.; 346 gr.--Brande; 3385 gr.--Ure). Its density to that of atmospheric air is, therefore, as about 11 to 10. It is a powerful supporter of combustion, and its presence is essential to the existence of both animal and vegetable life. It forms 21% (2081%) by volume, and 23% by weight, of the atmosphere. (M. Dumas.) Water dissolves about 5 per cent. by volume of oxygen, and by pressure a much larger quant.i.ty, forming oxygenated water (AQUA OXYGENII). Oxygen has recently been liquified.

_Tests._ 1. It is distinguished from other gases by yielding nothing but pure water when mixed with twice its volume of hydrogen and exploded, or when a jet of hydrogen is burnt in it.--2. A recently extinguished taper, with the wick still red hot, instantly inflames when plunged into this gas.--3. A small spiral piece of iron wire ignited at the point, and suddenly plunged into a jar of oxygen, burns with great brilliancy and rapidity. Charcoal does the same.

_Estim._ The estimation of the quant.i.ty of oxygen in an organic compound has already been described. For determining the quant.i.ty present in atmospheric air, and other like gaseous mixtures, Dobereiner has proposed the use of pyrogallic acid. The air under examination (freed from moisture) is measured into an accurately graduated tube over mercury, capable of holding about 30 cubic centimetres, and which it should 2/3rds fill. A solution formed of 1 part of dry hydrate of pota.s.sium and 2 parts of water, and in volume about 1/35th that of the air, is next introduced by means of a pipette with a curved point, and is gently agitated therewith in the gas for a short time; the decrease of volume gives the proportion of carbonic anhydride present. A solution of pyrogallic acid (1 gramme in 5 or 6 centimetres of water), equal in volume to one half that of the solution of pota.s.sa already used, is then introduced by means of another pipette, and the mixed liquids are cautiously shaken together over the inner surface of the tube. When absorption ceases (which it does in a few minutes), the quant.i.ty of residual gas (nitrogen) is read off from the graduations; the difference in volume before and after the introduction of the pyrogallic acid indicates the proportion of oxygen. This is a mere modification of Prof. Liebig's method. 1 gramme of pyrogallic acid in combination with hydrate of pota.s.sium is capable of absorbing about 189 cubic centimetres of oxygen. (Dobereiner.) Other methods employed for the a.n.a.lysis of air, depending on the increase or loss of weight when the air is pa.s.sed over finely divided copper heated to redness, the loss of volume when the air is exploded in a eudiometer with half its bulk of hydrogen, or when a stick of phosphorus is left in it for some hours, are well known, and described at length in every elementary work on chemical a.n.a.lysis. The last method, although less accurate than the others, has the advantage of extreme simplicity.

_Uses._ Oxygen has been employed to increase the illuminative and heating power of lamps, and to render vitiated air respirable, &c.; and when largely diluted with atmospheric air, or condensed in water, as a remedial agent in asphyxia arising from the inhalation of carbonic acid and carbonic oxide.

Dr Ringer says that if oxygen be administered as a gaseous bath for an hour or two at a time, and the bath repeated six or eight times a day, it is of great service in senile gangrene.

_Concluding Remarks._ Oxygen gas may be collected in the usual way, either over water, mercury, or in bags; or, on the large scale, in gasometers.

The purity of the products of the several processes given above depends on the substances from which the gas is obtained being themselves pure. For particular experiments the first portion of gas should be allowed to escape, or be received apart, as with this, as with the other gases, it is contaminated with the atmospheric air of the apparatus. The gas procured from manganese or nitre may be purified by pa.s.sing it through milk of lime or a solution of caustic potash; it will still, however, retain some traces of nitrogen. M. Limousin[81] has devised an apparatus for the preparation of oxygen by the attendants of hospitals, which obviates the risk of bursting of the retorts, attending its preparation by the old method. The apparatus consists of two cast-iron hemispheres, whose edges, which are well polished and about two centimetres thick, can be fitted hermetically upon each other, and fastened by three screws. The mixture of chlorate of potash and peroxide of manganese is placed in the lower hemisphere, which rests upon a tripod; the upper hemisphere, from which projects an iron tube, is now screwed on, and the iron tube connected with india-rubber and gla.s.s tubing with a Wolf's wash-bottle, from which the gas after being washed pa.s.ses through a second gla.s.s tube, and is thus ready for use. It may be conducted into an air-tight bag, in which it will keep for several weeks. Such a bag when supplied with a tube and stop-c.o.c.k will afford a ready means for inhalations. Oxygen in a condensed or compressed state is prepared by Mr Orchard, High Street, Kensington. See ORGANIC SUBSTANCES, OZONE, GASES, LIQUEFACTION OF, &c.

[Footnote 81: 'Pharm. Centralhalle,' xiv, 318.]

=OXYGENA'TION.= _Syn._ The act or process of combining with oxygen.

Formerly it was of more general application than the word 'oxidation,'

with which it has been regarded as synonymous. 'Oxygenation' is, however, at the present day practically obsolete.

=OXYGENI'SED LARD.= _Syn._ OXYGENATED AXUNGE; AXUNGIA OXYGENATA, L.

_Prep._ (Ph. Bat. 1805.) From prepared lard, 16 parts, melted over a slow fire, and then mixed with nitric acid, 1 part; the combination being promoted by constant stirring with a gla.s.s rod, until it ceases to affect litmus paper. It should be extremely white, and should be kept in the dark. See OINTMENT OF NITRIC ACID.

=OXYHYDROGEN BLOWPIPE.= See BLOWPIPE. Deville and Debray ('Ann. Ch. Phys.'

[3], lvi, 385) employ the oxyhydrogen blowpipe in the following manner for effecting the fusion of platinum and the refractory metals which accompany it. The apparatus consists of the blowpipe _C_ (see _below_), a furnace _ABD_, and a crucible _GHI_. The blowpipe is composed of a copper tube about half an inch in diameter, terminating below in a slightly conical platinum jet about 1-1/2 inch long. Within this tube, which is supplied with hydrogen or coal-gas through the stop-c.o.c.k _H_, is a second copper tube _C'_ for supplying oxygen, terminated also by a platinum nozzle with an aperture of about a twelfth of an inch in diameter.

[Ill.u.s.tration]

The furnace _ABD_ consists of three pieces of well-burnt lime of slightly hydraulic quality, which may be turned at a lathe with ease. The cylinder _A_ is about 2-1/2 inches thick, and is perforated by a slightly conical hole into which the blowpipe fits accurately, pa.s.sing about half-way through the thickness of the ma.s.s. A second somewhat deeper cylinder of lime, _B_, is hollowed into a chamber wide enough to admit the crucible, and leave an interval of not more than a sixth of an inch clear around it.

_KK_ are four apertures for the escape of the products of combustion.

The outer crucible _HH_ is also made of lime, but it contains a smaller crucible _I_ of gas c.o.ke, provided with a cover of the same material; and in this the substance to be used is placed, the crucible resting on the lime support _D'_. The conical cover _G_ is made of lime, and its apex should be placed exactly under the blowpipe jet, at a distance from it of 3/4 to 1-1/2 inch.

The different pieces of the furnace must be bound round with iron wire to support them when they crack. The oxygen is admitted under a pressure of a column of 16 inches of water. The temperature is gradually raised to the maximum, and in about eight minutes from this time the operation is complete.

[Ill.u.s.tration]

By employing a jet of mixed coal-gas and oxygen (_EQ_, see _engr._) in a furnace of lime, Deville and Debray succeeded, at an expense of about 43 cubic feet of oxygen, in melting and refining, in 42 minutes, 254 lbs.

avoirdupois of platinum, and casting it into an ingot in a mould of gas c.o.ke; and much larger ma.s.ses have since been melted by this method. Lime is so bad a conductor of heat that if a cup of lime not more than 08 inch thick be filled with melted platinum the exterior scarcely rises beyond 300 Fahr. (Miller's 'Elements of Chemistry,' 3rd. ed., pt. ii, p. 825.)

=OX'YMEL.= _Syn._ OXYMEL, L. An acidulous syrup made of honey and vinegar.

There are only two oxymels in the last Ph. L. The ingredients in an oxymel should be of such a character, and in such proportions, as to produce a mixture of the proper consistence without evaporation.

=Oxymel of Col'chic.u.m.= _Syn._ OXYMEL COLCHICI CORMI, OXYMEL COLCHICI, L.

_Prep._ (Ph. D. 1826.) Fresh corms (roots) of meadow saffron, 1 oz.; distilled vinegar, 1 pint (wine measure); macerate for 2 days, press out the liquor, filter, add of clarified honey, 2 lbs., and boil down the mixture to the consistence of a syrup, frequently stirring.--_Dose_, 1 to 3 dr., twice or thrice a day; in gout, rheumatism, dropsy, &c.

=Oxymel of Gar'lic.= _Syn._ OXYMEL ALII, L. _Prep._ (Ph. L. 1746.) Sliced garlic, 1-1/2 oz.; caraway seed and sweet fennel seed, of each 2 dr.; boiling vinegar, 8 fl. oz.; infuse, strain, and add of clarified honey, 10 oz. In hooping-cough, chronic diarrha, rheumatism, &c.

=Oxymel of Narcissus.= (Van Mons.) _Syn._ OXYMEL NARCISSI. _Prep._ Vinegar of Narcissus (made with 1 part of fresh flowers of daffodil to 8 of vinegar), 1 part; honey, 4 parts. Dissolve.--_Dose._ A teaspoonful. In hooping-cough and spasmodic asthma.

=Oxymel, Pec'toral.= _Syn._ OXYMEL PECTORALE, O. INULae COMPOSITUM, L.

_Prep._ (Ph. Br.) Elecampane, 1 oz.; orris root, 1/2 oz.; water, 1-1/2 pint; boil to 1/2 pint, strain, add of honey, 16 oz.; ammoniac.u.m, 1 oz.; (dissolved in) vinegar, 3 fl. oz.; lastly, boil to an oxymel.--_Dose_, 1 spoonful, occasionally; in coughs, humid asthma, &c.

=Oxymel, Sim'ple.= _Syn._ VINEGAR SYRUP, ACETATED HONEY; OXYMEL (Ph. L. & D.), OXYMEL SIMPLEX, MEL ACETATUM, L. _Prep._ 1. (Ph. L.) Acetic acid (sp.

gr. 1048) 7 fl. oz.; distilled water, 8 fl. oz.; mix, and add them to honey, 5 lbs., previously made hot. This contains only one half the acid ordered in the Ph. L. 1836.

2. (Ph. D.) Clarified honey, 1 lb.; acetic acid (sp. gr. 1044), 3 oz.; as before. Stronger than the last.

3. (Ph. L. 1836.) Honey, 10 lbs.; acetic acid (1048), 1-1/2 pint; as before. This contains too much vinegar. (See No. 1.)

4. (Wholesale.) From honey (thick and good), 12 lbs.; melt it by a gentle heat, add of distilled vinegar (of fully 5%), 2 quarts, and strain the mixture through flannel. No evaporation is required.

_Uses, &c._ Demulcent and refrigerant.--_Dose_, 1 to 4 fl. dr., either gradually sucked from the spoon or dissolved through some simple liquid.

Dissolved in water, it forms a useful and pleasant cooling drink or gargle in fevers, sore throats, hoa.r.s.eness, &c.; but in some individuals it occasions griping. It is commonly used as an adjunct, in mixtures, &c.

=Oxymel of Squills.= _Syn._ HONEY OF SQUILLS; OXYMEL SCILLae (B. P.), MEL SCILLae (Ph. L.), O. SCILLITIc.u.m (L.) _Prep._ 1. (B. P.) Mix and evaporate on a water bath vinegar of squills, 1 pint, and clarified honey, 2 lbs., till the product when cold has a specific gravity of 132.

2. Vinegar of squills, 2-1/2 pints; gently evaporate it to 12 fl. oz., and add of honey (previously made hot), 5 lbs.

3. (Ph. L. 1836.) Strained honey, 3 lbs.; vinegar of squills, 1-1/2 pint; boil to a proper consistence. The formula of the Ph. D. 1826 was similar.

_Uses, &c._ Expectorant, and in large doses nauseant.--_Dose_, 1/2 to fl.

2 dr.; in chronic coughs, hoa.r.s.eness, humeral asthma, &c.

=Oxymel of Ver'digris.= See LINIMENT OF VERDIGRIS.

=OXYR'RHODYNE.= _Syn._ OXYRRHODINON. An old compound formed of 1 part of vinegar of roses and 2 parts of oil of roses.

=OXYSAC'CHARUM.= A syrup acidulated with vinegar. See SYRUP.

=OXYSUL'PHIDE.= A name given to certain compounds or mixtures of metallic oxides and sulphides. See ANTIMONY, OXYSULPHIDE, &c.