AMM0NI.E SESQUICARBONAS.

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the Dublin Pharmacopoeia, a similar compound is prepared by mixingthree ounces and a half of coarsely-powdered sesquicarbonate of ammo-nia with three pints of heated rectified spirit; by the disengagement ofsome carbonic acid, carbonate of ammonia is produced, which dissolvesin the spirit, every fluid ounce of which is capable of taking up thirtygrains of the carbonate.

The spiritus ammonia of either of the above pharmacopoeias is a trans-parent, colourless liquid, having a pungent smell and acrid taste. Itreddens turmeric paper, and dissolves camphor and the volatile oils. Itsmedicinal effects and uses are analogous to caustic ammonia and the ses-quicarbonate. It is less pungent than the solution of caustic ammonia,but more so than the liquor ammonia; sesquicarbonatis. It is employedin hysteria, flatulent colic, and nervous debility, in doses of from half adrachm to a drachm, properly diluted with water. Saturated with cam-phor it forms a highly stimulating liniment.

2. Spiritus ammonia aromaticus (Ph. L.).—-This compound, usuallytermed spirit of sal volatile, is very analogous to the last, from which itdiffers in the somewhat different proportions of the ingredients, and theaddition of some aromatics. It is prepared from five ounces of hydro-chlorate of ammonia, eight ounces of carbonate of potash, two drachmsof bruised cinnamon, two drachms of bruised cloves, four ounces oflemon-peel, four pints of rectified spirit, and four pints of water. Mix,and let six pints distil. In this process, double decomposition takes place,as already noticed, and the carbonate of ammonia distils over with thespirit and part of the water, flavoured by the aromatics. This prepara-tion is weaker than the preceding, but is more agreeable both to thetaste and smell. Its effects, uses, and doses, are analogous to those ofthe last-mentioned compound. It is an ingredient in the ammoniatedtincture of guaiacum and the compound tincture of valerian.

3. Spiritus ammonia fcetidus (Ph. L.).—This is prepared in the sameway as the spiritus ammoniac, except that five ounces of asafcetida areput into the retort with the other ingredients. It is prepared in theDublin Pharmacopoeia by digesting one ounce and a quarter of asafcetidain two pints of spirit of ammonia, and distilling one pint and a half.This foetid spfrit of ammonia has been very correctly declared to be useless.It is merely a solution of the volatile oil of asafcetida in spirit of ammonia,for which a mixture of the tincture of asafcetida and spirit of ammoniamay be conveniently substituted. It is colourless, pungent, and foetid,and by age becomes brownish. It is employed in hysteria in doses ofhalf a drachm to a drachm in water.

Ammo'nia Sesquicar'bonas. — Sesquicar'bonate of Ammo'nia .

History and Synonymes. —Though this salt must have been longknown, yet, until a few years since, it was confounded with the carbonateof ammonia. It is even now frequently called carbonate or subcarbonateof ammonia in the shops. It is sometimes termed volatile or smellingsalts; and occasionally bakers' salt, on account of its use by bakers inthe manufacture of some of the finer kinds of bread.

Natural History. —(S ee Ammonia and Ammonia Carbonas.)

Preparation. —In the London Pharmacopoeia we are ordered to mixa pound of powdered hvdrochloratc of ammonia with a pound and a