1909.] 



PUBLIC DOCUMENT — No. 31, 



199 



had in the feeding of treated hay animals would eat sufficient to 

 cause fatal poisoning. 



Susceptibility. — In so far as it was possible to ascertain 

 there did not appear to be among the animals used in the experi- 

 ment an individual susceptibility to the action of the poison. 

 In some of the cows more was required to produce toxic effects 

 than in others, but this seems to be accounted for more on the 

 ground of weight and vigor than on that of individual suscep- 

 tibility. 



It is of interest to note in this connection the effect of arsenic 

 or lead on the different species of farm animals. Nunn, quot- 

 ing Kaufmann, gives the toxic dose of arsenic for each of the 

 domestic animals, when administered by the mouth, as fol- 

 lows : — 



Horse, 

 Ox, 



Sheep, 

 Dog, 



Pig, 



Fowl, 



Pigeon, 



For acetate of lead the toxic dose, according to the same 

 authority, is : — 



Grams. 



500 to 750 



Horse, 

 Cattle, 

 Sheep, 



Pig, 

 Dog, 



50 to 100 



30 



8 



10 to 25 



The harmless effects of the arsenate of lead fed to a horse by 

 Mr. Kirkland, referred to in another part of this bulletin, is 

 in all probability to be accounted for, in part at least, by the 

 natural nonsusceptibility of the animal to the action of lead, to 

 which the ruminants appear to be particularly susceptible. 



