June, 1917.] aksenical residues after spraying. 53 



paralysis and its breathing was spasmodic. Neither sheep would 

 eat. On the fifth day the conditions were similar, but a little 

 worse. 



Both sheep were now moved to a stock pen free from spray 

 material, in order to observe recovery. The first day both were 

 a little improved. The second dsij they began to eat and in 3 

 days more the symptoms of poisoning had disappeared, appetite 

 had returned and both sheep appeared normal. 



In the third lot 2 gallons of spray material was applied con- 

 taining 3| oz. of dry arsenate of lead, or at the rate of 10 lbs. of 

 arsenate of lead paste to 50 gallons of water. 



Each of the two sheep placed in this pen showed prompt and 

 definite symptoms of poisoning. By the end of the first day 

 both were languid and would eat but little. They drank no 

 water. One of them stood with drooping head. On the second 

 day both were definitely sick. Paralysis began to appear. 



Another 24 hours found one of the sheep in a bad way. It was 

 unable to stand. Its breathing was spasmodic. The other 

 sheep was somewhat better off. On the fourth day one of the 

 sheep died, exhibiting definite symptoms of poisoning. The 

 other sheep was now removed to the stock pen free from sprayed 

 grass. Within a day it showed considerable improvement. 

 It began to eat and could walk without staggering. This im- 

 provement continued steadily, with the result that in 4 days 

 more this sheep appeared quite normal. It was maintained' 

 under observation for 3 weeks longer and showed no further 

 symptoms of poisoning. 



To get at the subject from another angle. Arrangements were 

 made to pasture sheep beneath the trees that had been sprayed 

 with definite amounts of arsenate of lead. The results are 

 shown in Table No. 14. A discussion of the results in detail 

 follows : 



A pen was set up up beneath an apple tree which was then 

 sprayed with arsenate of lead, at-the rate of 6 lbs. of the paste 

 to 50 gallons of water. The tree was of medium size and was 

 sprayed carefully with the purpose of avoiding unnecessary drip. 

 The amount of spray material used was Ij gallons. One sheep 

 was placed in the pen. This animal had been pastured on sprayed 

 grass earlier in the season, but for 36 days had had no access to 



