398 
L. H. FRIEDBUfcG. 
insects. The snail easily tolerates doses of strychnin whicl 
would kill a man instantly. 
In regard to strychnin, we are in possession of very in 
teresting facts showing that the sensitiveness of different an 
imals towards this particular poison is quite different. Oi 
hypodermic injection, the fatal doses are, per kilogramme o 
the animal: rabbit, 0.6 mgrms.; dog and cat, 0.75 mgrms. 
fox, 1.0 mgrms.; hedgehog and frog, 2.0 mgrms.; whitefish 
12.5 mgrms.; ringadder, 23.0 mgrms.; bai, 40.0 mgrms. 
As a rule, newly born warm-blooded animals are but litth 
susceptible to the influence of strychnin, so that they toler 
ate, relatively speaking, larger doses than adults. Horses al 
low, without detriment, hypodermic injections of 0.1 to o.: 
mgrms. per kilo., showing only temporary symptoms. Very 
old, weak horses, or such suffering from spinal marrow dis 
ease, will die after 0.3 mgrms. per kilo., hypodermic, whih 
young horses, as a rule, tolerate this dose without danger 
Every horse, however, will be killed within a short time b} 
hypodermic injections of 0.4 mgrms. per kilo. 
For one and the same species, the size of the fatal dos< 
will vary with a number of other varying conditions. Witl 
the exception of very old age we can say that the resistance 
of the organism against a poison increases with the age. I 
a given poison has the action 1 upon a six-year-old horse, i 
will be for a one-year-old =J-, for a half-year old, J, for a quar 
ter-year-old^=-|-, for a one-month-old^^, etc. There are, how 
ever, exceptions to this rule, since, e.g., young dogs will toler 
ate larger doses of calomel than older ones. As a genera 
rule, one and the same dose of a poison acts less strongly up 
on a larger animal than upon a smaller one. If we put thi 
horse or cattle=i, we have the following proportional num 
bers: sheep and goats, \; pigs, -J-; dogs (and man) T V; cat: 
and poultry, ^L-. We practically use this knowledge in th< 
destruction of animals, thus, e.g., in the use of prussic acid fo 
this purpose. We can kill a 1,600 pound horse by means of on* 
gramme of the concentrated, anhydrous prussic acid, (whicl 
the chemist has to prepare himself, it not being dispensed) 
while we must use 100 to 200 times this quantity if we want t< 
