Oleum Aethereum . Lond. Aethereal Oil

"Take of rectified spirit, two pounds; sulphuric acid, four pounds; distil again the solution of potassa, and distilled water, of each a fluid ounce, or as much as may suffice. Mix the acid and the spirit cautiously together. Let the liquor distil until a black froth swells up: then immediately remove the retort from the fire. Separate the lighter liquor from the heavier; and expose the former to the air for a day. Add to it the solution of potassa mixed with water, and shake them together. When sufficiently washed, separate the aethereal oil which subsides. Lastly, take off the aethereal oil after it has separated."

Liquor Ethereus oleosus, Dub. Oily Aethereal Liquor, "Take what remains in the retort after the distillation of sulphuric aether. Distil to one half, by a moderate heat."

Syn. Huile douce de vin (.F.), Oleo dolce di vino (I.).

The product of both these processes is a thick oily matter, of a yellow colour, slightly viscid; of sp. gr. 1.05, less volatile than aether, soluble both in aether and alcohol; but insoluble in water. It is supposed to be a perfectly neutral compound of carburet of hydrogen and sulphuric acid; it consists of 1 eq. of sulphuric acid = 40 + 9 of carbon = 55.8 + 9 of hydrogen = 9; making the equivalent 104.9. After being kept for a few months, aethereal oil becomes viscid, and prismatic crystals form in it, which are soluble in aether and alcohol, melt at a slight heat, and sublime unaltered. In sulphuric acid they dissolve, forming a pink solution; and in nitric a deep red: but they are insoluble in hydrochloric and acetic acids and in the alkalies. It can be obtained more directly, although less economically, by distilling aether with a portion of sulphuric acid. It is used only for the preparation of the compound spirit.

1 Oleum vini, P. L. 1787.

Officinal preparation. - Spiritus Aetheris Sulphurici compositus, L.D.

Aether Sulphuricus Cum Alcohole Aromaticus. Edin. Aromatic Sulphuric Aether with Alcohol

"Take of cinnamon bark, bruised, cardamom seeds, bruised, each an ounce; long pepper, bruised, two drachms; sulphuric aether with alcohol, two pounds and a half. Digest for seven days, and filter through paper."

This preparation does not differ in its medicinal properties from the former; the aromatics rendering them only a little more grateful.

Spiritus Aeheris Nitrici . Lond Spirit of Nitric Aether

" Take of rectified spirit, three pounds; nitric acid four ounces. Add the acid gradually to the spirit, and mix; then distil thirty-two fluid ounces."

Spiritus Aether is Nitrosi, Edin. Spirit of Nitrous Aether.

"Take of alcohol, three pounds; nitrous acid, one pound; pour the alcohol into a large phial placed in a vessel full of cold water, and add the acid gradually, with frequent agitation. Let the phial be slightly corked and placed in a cool place for seven days: then distil the liquor by the heat of boiling water, into a receiver kept cool with snow or water, as long as any spirit comes over."

Spiritus Aethereus Nitrosus, Dub. Nitrous Aethereal Spirit.

" Add to the matter which remains after the distillation of nitrous aether the rectified spirit of wine employed in that operation for condensing the elastic vapour, and distil to dryness with the greater heat of a water bath. Mix the distilled liquor with the alkaline liquor which remains after the separation of the nitrous aether, and also add as much dry subcarbonate of kali as shall be sufficient to saturate the predominant acid; which is to be determined by the test of litmus. Lastly, distil by the medium heat of a water bath, as long as any fluid comes over. The specific gravity of this liquor is to that of distilled water, as .850 to 1000."

1 Spiritus nitri dulcis P. L. 1745. Spir. actheris nitrosi, 1787.

Syn. Alcohol ethereux par l'acide nitrique (F.), Atherischer saltpeter spiritus (G.), Spirito di nitro dolee(J.).

The products of the London and Edinburgh processes are in every respect the same; but the former is to be preferred on account of the length of time required by the latter. The small quantity of acid in proportion to the alcohol employed permits the mixture to be effected without any violent action taking place, or the evolution of much heat, provided the acid be added in small quantities, and at intervals, and each portion be thoroughly mixed with the alcohol before another be added. The heat employed for the distillation should not exceed 212°, and it should be stopped as soon as thirty-two fluid ounces come over; for when it is longer continued, the product becomes coloured, and contains too much free acid.1 The theory of the operation, inasmuch as relates to the production of the nitric aether, which is thus obtained in combination with a large proportion of unchanged alcohol and a small proportion of nitric acid, is nearly the same as that already detailed; except that a partial decomposition of both the alcohol and the acid takes place.

The entire product has the same relation to nitric aether as spirit of sulphuric aether has to sulphuric aether.

The product obtained by the first part of the Dublin process is analogous to the above. The acid which the residue of the distillation of nitrous aether contains, and the alcohol already impregnated with a small portion of that fluid, when mixed and heated, act reciprocally on each other, and a compound of nitric aether, unchanged alcohol, and free acid, distils over; but the alkali with which it is mixed before the second distillation removing the acid, its properties, both as a chymical compound and as a remedy, must be necessarily altered. The products of the former processes are those which have been longest known and most extensively employed.

Qualities. - Spirit of nitric aether, as procured by the London or the Edinburgh process, has an extremely fragrant, odour, and a pungent, acidulous taste. Its spec. grav. should not exceed 0.834. It is very volatile and inflammable; and soluble in water and in alcohol. It coagulates tincture of guaiacum, giving it at the same time a deep blue colour; and it also strikes a deep olive with solution of green sulphate of iron.1 Nitric aether, according to Thenard, consists of carbon 28.45, oxygen 48.52, hydrogen 8.54, and azote 14.49 in 100 parts; and according to a late analysis by MM. Dumas and Boullay, the spirit of nitric aether is a compound of four equivalents of carbon = 24.48+5 of hydrogen = 5 + 1 of nitrogen =. 14.15 + 4 of oxygen = 32 = 75.63. The proportions of this aether in the spirit have not been determined.

1 London Medical Review, April, 1810, p. 164.

Medical properties and uses. - Spirit of nitric aether is refrigerant, diuretic, and antispasmodic. It has long been employed under the title of Sweet Spirit of Nitre, as a grateful refrigerant, and to quench thirst in febrile affections; for which purpose the dose is from xx. to xl., given in a cupful of water, or any other appropriate vehicle. In larger doses, it acts as a gentle stimulant to the stomach, relieving nausea and flatulence; and also determines to the kidneys, increasing the flow of urine; on which account it is advantageously prescribed as an auxiliary to other diuretics in dropsical complaints.