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ELEMENTS OF MATERIA MEDICA.

allaying nausea and vomiting; they are also feebly diaphoretic, and insome cases diuretic.

Sesquicarbonate of ammonia has been employed as an emetic in para-lysis. An ointment made of the finely pulverized salt and lard is a veryuseful rubefacient in rheumatic pains, sprains, &c. Mixed with somearomatic oil (as oil of lavender or bergamot) it is employed as a smelling-salt against syncope, hysteria, &c.

Administration. —As a stimulant and diaphoretic this salt is used indoses of from five to ten grains, exhibited either in the form of pill or ofsolution. As an emetic the dose is 30 grains, properly diluted, andrepeated if necessary.

Antidotes. —(See Ammonia .)

Ammoniacal Soaps. —When caustic ammonia is mixed with fattybodies (such as olive oil, lard, or mutton suet), it forms a kind ofsoap, composed of the fatty acids, generated by the oil and of ammoniacombined with them. Two of these compounds require to be noticed:—■

1. Liniment of ammonia. —This is prepared, according to the LondonPharmacopoeia, by mixing a fluid ounce of solution of ammonia withtwo fluid ounces of olive oil. This compound, sometimes termed volatileliniment, is an oleo-margarate of ammonia; that is, a compound of oleicand margaric acids with ammonia. It is employed as an external sti-mulant and rubefacient, to relieve rheumatic and neuralgic pains, sorethroat, and various other complaints in which cutaneous stimulants arelikely to be useful. It is the

2. Ointment of ammonia. —In France an ointment is employed, calledliparole d'ammoniaque, or pommade ammoniacale de Grondret, and whichis composed of eight parts of solution of ammonia, seven parts lard, andone part mutton suet. This compound, rubbed on the skin, and coveredby a compress, speedily produces vesication: without the compress itcauses rubefaction, merely owing to the volatilization of the ammonia.It is a very useful counter-irritant and vesicant.

Liniment of sesquicarbonate of ammonia. —This is prepared by mixinga fluid ounce of the solution of the sesquicarbonate of ammonia withthree fluid ounces of olive oil. It forms an imperfect kind of soap,owing to the presence of carbonic acid. Its uses are analogous to thoseof the liniment of ammonia before mentioned.

Ammo'nice Bicar'bonas. — Bicar'bonate of Ammo'nia .

History and Synonymes. —This salt was formed by Berthollet , andhence it is sometimes termed Berthollet 's neutral carbonate of ammonia.

Preparation. —In the Dublin Pharmacopoeia it is ordered to be pre-pared by passing a stream of carbonic acid through a solution of fourparts of sesquicarbonate in fifteen parts of water, until the sesquicar-bonate be saturated. It is then allowed to remain at rest, and crystalsare deposited, which are to be dried without heat, and preserved in aclose vessel.

Properties. —This salt crystallizes in irregular six-sided prisms. Ithas little or no smell, and less taste than the sesquicarbonate. It is lesssoluble than the last-mentioned salt, and its solution does not precipitatethe magnesian salts, by which circumstance it may be distinguished fromthe carbonate of ammonia. »