350 MANUAL OF EQUINE MEDICINE. 



Stained; the mare died at 2 a.m. on the following day, and the 

 autopsy revealed pathological conditions somewhat similar 

 to, but much less marked than, those described in the pre- 

 vious case. 



The other three animals made a gradual recovery, and 

 were soon again at work. 



It was ascertained in these three instances that arsenic 

 had been administered in the form of powdered arsenious 

 trioxide. The waggoner had for some time previously given 

 to each of his horses every night as much as he could place 

 on the end of a large pocket-knife. But on the night when 

 the horses were so suddenly affected he had given an extra 

 dose to each, three or four hours previous to the appearance 

 of symptoms of poisoning. Probably each horse had 

 received from two to three drachms. 



Several months afterwards we took the opportunity of 

 examining two of the horses again ; both had an intermit- 

 ting pulse, irregular in rhythm and volume. The foreman 

 told us that they had never regained their previous 

 strength. Their appetite was somewhat impaired, and 

 when out at work they were far more easily fatigued 

 than the other horses, and breathed violently when any 

 additional strain was put upon them. 



After the administration of vegetable and mineral 

 tonics, they made considerable improvement. Their condi- 

 tion was doubtless in part or wholly due to the effects of 

 the arsenious acid on the endocardium lining the left ventricle 

 of the hearty and, indeed^ a distinct mitral murmur coidd he 

 heard in one of the cases. This murmur was systolic in time. 

 That arsenic, when given in solution, acts much more 

 rapidly and powerfully is shown by the following record 

 of nine cases of poisoning which occurred in Mr. D. Gress- 

 well's practice some years ago. 



One of the waggoners on a large farm, having obtained a 



