AMMONI.E SESQClCARBONAS.

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it should be translucent, and not opaque and pulverent; and, lastly, itssolution, saturated with pure nitric acid, should give no precipitate withchloride of barium or nitrate of silver, for the first would indicate sul-phuric acid or a sulphate, the second hydrochloric acid or a chloride.

Physiological Effects (a.) On vegetables. —[See Ammonia.]

(b.) On animals. —The principal experimenters with this salt areSeybert, Orfila, and Gaspard, on dogs, and Wibmer on man. Seybert(quoted by Wibmer, die Wirkung, &c.) injected in one experimentfifteen grains, in a second twenty-five grains, and in a third experimentforty-live grains of this salt, dissolved in a little water, into the cruralvein of a dog : the animal appeared to suffer great pain; the frequencyof the heart’s action was increased, the respiration became difficult, andviolent convulsions came on ; but in all these cases perfect recoverytook place. The blood drawn after the injection had the natural colour,odour, and consistence. Orfila ( Toxicol. Gener.) found that two drachmsand a half of the salt, given to a dog, caused gastric inflammation, withtetanic convulsions; the body ultimately becoming curved, with thehead forcibly bent backwards. Gaspard (quoted by Wibmer) killed ayoung pig, of three weeks old, by injecting twenty-four drops of (a solu-tion of) carbonate of ammonia in an ounce of water into tlie veins.Death occurred in nine hours.

(■ c.) On man. —The principal experimenter here is Wibmer [op. cit.),who made his trials on himself. He found that a grain and a half of thissalt produced no remarkable effect; three grains increased the frequencyof the pulse from 68 to 72 beats per minute, with throbbing headache.In other experiments, in which he took from six to twelve grains (insome repeating the dose at short intervals), the effects were usually, butnot constantly, increased frequency of pulse, with disorder of brain,manifested by the pain, heaviness, throbbing, &c. In one instance, he says,disposition to cough, and increased secretion of bronchial mucus, wereremarkable.

From these and other experiments we infer, that the local action ofthis salt is that of an irritant and corrosive ; but it is much less powerfulthan the caustic solution of ammonia, in consequence of the presence ofcarbonic acid, which in some degree neutralizes the alkaline properties ofthe ammonia. Swallowed in moderate doses (of about 30 grains) itoccasions vomiting: in large doses it excites pain, inflammation, and allthe consequences of an irritant poison; while the immoderateinhalation of its vapour is capable of giving rise to bronchialinflammation. The remote action of this salt is similar to that of causticammonia. Thus, in small doses it has the same exciting action on theheart, brain, &c. and the same diaphoretic effect. We denominate it,therefore, stimulant, sudorific, antispasmodic, antacid, and rubefacient.

Uses. —Sesquicarbonate of ammonia is used in the same cases andunder the same circumstances as the solution of ammonia, to which,therefore, I must refer the reader. In some cases it is also employed inthe production of effervescing draughts. The following are the relativeproportions of acid and base to be used :—

20 grains of sesquicarbonate of ammoniawill saturate about.

6 fluidrachms of lemon juice.

|24 grains of crystallized citric acid..252 grains of crystallized tartaric acid.

The citrate and tartrate of ammonia, obtained as above, are useful in