684 POISONS : THEIR EFFECTS AND DETECTION. [§§ 871 , 872 . 
(10 to 20 grains) as an alterative ; Ethiops mineral 7-7 to 15-5 grms. 
(2 to 4 drms.). 
Dogs. —Ethiops or Turpeth mineral -13 to 1-3 grm. (2 to 20 grains), 
according to the size. 
Fowls. —Mercury and chalk are given in fractions of a grain. 
Hogs are also treated with mercury and chalk ; the dose usually 
given does not exceed -32 grm. (5 grains). 
It may he remarked that many of the doses quoted appear very 
large ; the writers cannot hut consider that 20 grains of corrosive sub¬ 
limate administered to a horse would be more likely to kill the animal 
than to cure the disease. 
Man. —Corrosive sublimate has been fatal in a dose so small as 
•19 grm. (3 grains) ; white precipitate has caused dangerous symptoms 
in doses of from 1-9 to 2-6 grms. (30 to 40 grains) ; the cyanide of mercury 
has killed a person in a dose of '64 grm. (10 grains) (Christison) ; and 
Turpeth mineral has proved fatal in doses of 2*6 grms. (40 grains). 
Other preparations of mercury have also been fatal, but a doubt has 
existed as to the precise quantity. Sometimes, also, there is probably a 
chemical change in the substance, so that it is impossible to state the 
fatal dose. For example, it is well known that calomel, under the in¬ 
fluence of alkaline chlorides, can be converted into the bichloride—a 
fact which probably explains the extensive corrosive lesions that have 
been found after death from large doses of calomel. 
§ 871. Poisoning by Mercury — Statistics. — In the Registrar- 
General’s death returns for the five years ending 1916, it appears that 
in England the deaths from mercurial poisoning 1 were 23 males, 
33 females ; of these, 19 males and 27 females were cases of suicide, 
the remainder were referred to accident. 
§ 872. Effects of Mercurial Vapour, and the Non-Corrosive 
Compounds of Mercury. 
The effects of the different compounds of mercury may be divided 
into two groups, viz. : (1) those caused by the finely divided metal and 
* the non-corrosive compounds ; (2) the effects caused by the corrosive 
compounds. 
(a) Vegetable Life. —Priestley and Boussingault have shown that 
plants under a glass shade in which mercury is exposed in a saucer, 
first exhibit black spots on the leaves ; ultimately, the latter blacken 
entirely, and the plants die. 
( b) Animal Life. —Mercury in the form of vapour is fatal to animal 
life, but it is only so by repeated and intense application. Eulenberg 2 
1 The deaths are registered under the term “ Mercury but the majority are 
poisonings by “ Corrosive Sublimate .” 
2 Op. cit., p. 728. 
