400 
D. E. SALMON. 
There can be no doubt, therefore, that 30 grains of arsenic in 
solution ingested by a horse or bovine animal daily will soon pro¬ 
duce severe symptoms of poisoning, and if continued will cause 
death; and that about half that quantity will produce symptoms 
of poisoning after a longer time. 
Efforts have been made by various investigators to obtain a 
more definite determination of the poisonous dose by injecting 
arsenical solutions subcutaneously, intravenously and intraperi- 
toneally, and such experiments seem to establish the fact that as 
the animal increases in size the fatal dose per unit of body weight 
decreases. 
Thus, Loffier and Rfihs (9) were able to give guinea pigs 6 
milligrams of arsenious acid per kilo of body weight by intraperi- 
toneal injection of their solution (dissolved in a solution of caus¬ 
tic soda and afterwards neutralized with hydrochloric acid) as a 
medicinal dose in the treatment of trypanosomiasis. In the same 
manner they were able to give 7.5 mgs. per kilo to rats. 
Weber and Furstenberg were able to give rats as much as 8 
mgs. per kilo in the peritoneum as a therapeutic dose. 
Roehl (10) gives as the maximum dose of atoxyl per kilo for 
mice and rats 0.17 gm. and for guinea pigs 0.08 gm. That is, 
rats and mice, the smallest of the experimental animals, are able 
to support from 25 per cent, to 100 per cent, larger doses of ar¬ 
senic per kilo of body weight than are guinea pigs, the animals 
which come next in size. 
G. Brouardel (11) found the fatal dose (solution with car¬ 
bonate of soda) for guinea pigs intraperitoneally to be 16 mg. 
per kilo, and subcutaneously 13 mg. per kilo. For rabbits sub¬ 
cutaneously, the fatal dose was 10 mg. per kilo. 
With dogs, Rouyer and Feltz (12) found that the absorption 
of 2.5 mg. per kilo sometimes and 3 mg*, per kilo always caused 
death. The writer has administered as much as 3.3 mg. per kilo 
subcutaneously (solution of Loffier and Ruhs) without causing 
death, although the same dog died 10 weeks later from a dose of 
2.9 mg. per kilo. 
The fatal dose of arsenious acid subcutaneously for these ex- 
