26 



MATERIA MEDICA. 



action of hydrochloric acid on cyanide of silver in water. Its pro- 

 perties are similar to those of the concentrated acid, only in a less 

 degree ; it contains from 2 to 3 parts of real acid in 100 of water. 

 It is very liable to decomposition, especially when exposed to the 

 light ; hence it should be kept in a dark place. 



Effects on Syston. — In very small doses repeated, it causes a 

 bitterish taste, nausea, vertigo, faintness, but no very certain altera- 

 tion of the circulation. The more violent effects are great and sud- 

 den prostration, giddiness, and faintness, tetanic convulsions, and 

 insensibility, difiicult and spasmodic respiration, and death. The 

 peculiar odour of the acid is usually very distinct. The post-mortem 

 appearances are not very definite. The best antidotes are chlorine, 

 ammonia, the cold affusion, and artificial respiration. 



Uses. — Internally, as a remedy in certain nervous affections, par- 

 ticularly gastrodynia ; also in hooping cough, asthma, epilepsy, hy- 

 pertrophy and palpitation of the heart, and in the cough of phthisis. 

 Externally, it is employed as a wash in certain forms of skin disease, 

 — the proportions being 3ij of the dilute acid to Oss. distilled water. 

 Dose of the officinal acid, 1 to 3 drops, repeated till some obvious 

 effect is produced. 



As a substitute for hydrocyanic acid, the cyanide of potassium 

 may be used, since it is not, like the former, apt to undergo decom- 

 position when kept. It may be given in the dose of? gr., gradually 

 increased. When swallowed it becomes converted into hydrocyanic 

 acid, by the acid of the stomach. Another good substitute is the oil 

 of bitter almonds — in the dose of | of a drop, to be repeated. 



ORDER III.— STUPEFACIENTS OR INTOXICANTS. 



These are agents which produce a peculiar disorder of the intellect, 

 termed intoxication^ impair volition, and when used in excess, occa- 

 sion paralysis of the voluntary muscles, and stupor. They are all 

 decided excitants to the circulation as well as to the cerebro-nervous 

 system ; and their influence seems to be more decidedly directed to 

 the brain than to the spinal marrow. This order includes many of 

 the agents denominated stimidant narcotics. They difl?er very much 

 in their energy over the system, and are, by some, supposed to pro- 

 duce their different effects on different parts of the brain. As medi- 

 cines, their chief employment is in reference to their narcotic, anodyne, 

 and stimulant properties. 



Alcohol. 



The product of a peculiar change in a saccharine liquid, known as 

 the vinous fe?' mentation. The conditions necessary for this change 

 are a solution of sugar, the presence of some ferment, and a certain 

 temperature. The chemical change which occurs is the conversion 

 of sugar into alcohol and carbonic acid. The juices of various fruits 



