524 MATERIA MEDICA 



POISONS. These are noticed in a Materia Medica for the 

 purpose of showing the means we are acquainted with of coun- 

 teracting their baneful effects. Poisons are of three kinds, viz. 

 mineral, vegetable, and animal. Of the first kind are arsenic, 

 corrosive snbllmate, and certain preparations of lead. The best 

 antidotes to arsenic are oily and mucilaginous liquids, sulphate 

 of potash, soap, and castor oil in a solution of sulphate of mag- 

 nesia.* The same means may be employed to counteract the 

 effects of sublimate. t When there is much purging, give lin- 

 seed tea, tripe liquor, or thin gruel, or gruel made of arrow-root. 

 Such immense doses of sugar of lead have been given by way of 

 experiment to glandered horses without producing any effect, 

 that the preparations of lead are not considered poisonous ; cer- 

 tain it is, however, that a great number of horses and cattle 

 have been poisoned by grazing near those places on the Hill of 

 Mendip, where lead ore is smelted. Great mischief has thus 

 been done in a village named Wookey, through which a small 

 river, or rather brook, runs. After very heavy rains, the water 

 that flows down the hill seems to be impregnated with lead ; 

 for at such times it overflows certain meadows, and on the water 

 retiring these meadows have poisoned horses, cattle, and other 

 animals. This fact is well known in the village and its neigh- 

 bourhood ; and animals thus poisoned are said to be minderedy 

 or vioindered. Animals very seldom recover from it, though 

 they sometimes linger a considerable time. I have been in- 

 formed that one farmer in Mendip lost fifteen head of cattle in 

 consequence of their breaking down the fence which surrounded 

 the smelting place, to get at the grass which grew within. They 

 suppose that it is the fine particles of the lead ore which does 

 the mischief; but I think it more probable that it depends upon 

 the fumes or volatile parts that are carried up in smelting, whicli, 



* Mr. Morton recommends lime water and liquids in large quantities ; also, 

 large doses of the hydrated peroxide of iron precipitated by ammonia from a 

 solution of the sulphate of iron. Avoid bleeding, but use other measures to 

 subdue inilammation, and afterwards give vegetable tonics. 



When death ensues the stomach and bowels are highly inflamed and ulcer- 

 ated. 



The presence of arsenic may be discovered by various tests. The contents 

 of the stomach should be boiled in distilled water and filtered. The ammo- 

 niacal sulphate of copper being added, causes a precipitate of an apple green 

 colour. 



There are other tests employed, the most delicate of which is by means of 

 Marsh's apparatus — Ed. 



t The best treatment for poisoning by corrosive sublimate, consists in ad- 

 ministering the albumen, or white, of eggs suspended in water, which renders 

 the sublimate insoluble. In addition to this, wheat flour, gruel, or milk may 

 also be given. 



The presence of sublimate may be discovered by lime-water, which causes 

 an orange-yellow precipitate. — Ed. 



