A styptic, urinous, and caustic taste; a severe heat in the throat; violent vomiting, generally of alkaline matter, turning the syrups of violets green, and where the alkali has been in the state of _carbonate_, effervescing with acids; sometimes the matter thus ejected is mixed with blood; copious alvine evacuations; severe pain in the epigastric region; excruciating tormina of the bowels; depravation of the intellectual faculties, and death. It will be easily perceived that the above symptoms merely indicate the operation of a corrosive poison. They offer no characteristic peculiarities which can enable us to decide upon the particular substance that has been swallowed, unless, indeed, the matter vomited can be submitted to examination. _Antidotes._ From the experiments of _Orfila_, it appears that vinegar, diluted with water, is the remedy which can be administered with the greatest success, where any preparation of this alkali has been swallowed in a poisonous dose. _Organic lesions discovered on dissection._ In consequence of the peculiar action of this alkali upon animal matter, we shall generally find the stomach perforated, and its coats extensively dissolved. We shall moreover discover the usual indications of violent inflammation in this viscus, as well as in the intestines. SODA. We have already stated by what chemical reagents this alkali may be distinguished from _potass_; it only remains for us to observe that its physiological action, the symptoms arising from its ingestion, and the organic lesions discovered on dissection, are strictly analogous to those we have described as the effects of potass. AMMONIA, and its CARBONATE. Ammonia, in its uncombined state, exists in the state of gas, and is incapable of application; its affinity, however, for water, enables it to combine with that fluid, and to form liquid ammonia, (_Liquor Ammoniæ_) in which state it is useful in medicine, and in the arts. This solution is colourless; its taste extremely caustic; and its odour strong, pungent, and peculiar. Exposed to the action of heat, the ammoniacal gas is driven off, and may be recognised by its characteristic odour, as well as by its effects upon moistened _turmeric_ paper. When brought into contact with muriatic acid, it will form dense white vapours, consisting of _muriate of ammonia_. A most elegant and sensible test for ammoniacal gas is afforded by a mixed solution, consisting of arsenious acid and nitrate of silver; these substances when mixed in solution do not occasion the least disturbance in each other, for reasons already explained, (see page 240) but upon spreading a portion of the liquid upon glass or paper, and bringing ammoniacal gas into contact, a beautiful yellow cloud immediately diffuses itself over the surface of the solution.