ARSENICAL POISONING FROM SMELTER SMOKE. 
169 
separate from the tissues beneath, the floor of the ulcer was 
granulating, and there was an increased secretion of pus. While 
the ulcers of this stabled horse were healing, fresh ulcers were 
developing in the nostrils of the horses on Para’s pastures. One 
of these animals examined on this date, in addition to small 
sores within the nostrils, had the skin of the entire nose for three 
inches above the nostrils inflamed, thickened, covered with crusts 
and deeply fissured. A similar condition extended under the 
lower jaw for about the same distance. October 12, the ulcers 
of the experimental horse were rapidly healing and were already 
reduced to half the size which they were when the horse was 
put in the stable. October 28 the ulcers were entirely healed. 
This experiment, which w!as confirmed by other observations, 
is quoted to show how readily these ulcers healed when the horses 
were removed from the influence of the smoke deposits. And 
the experiment is made the more conclusive by the fact that 
during all of the time that these ulcers were healing, those in 
the nostrils of the horses which were left on pasture, both on 
the Lappin and Para ranches, continued to develop, becoming 
larger and deeper with no signs of healing. 
Experiment to indicate if the ulcers were transmitted by 
cohabitation .—When the horse from the Lappin ranch was placed 
in Para’s stable, there w ! as put with it a yearling colt, and both 
animals were free, eating from the same hay rack and feed box 
during the whole period that the ulcers continued. The colt was 
under observation until December 5, but did not at any time 
present any symptoms of nasal ulceration. 
With these experiments indicating that the ulcerative lesions 
were neither contagious by cohabitation, nor inoculable by super¬ 
ficial scarifications or hypodermic injections, and proving that 
healing occurred as soon as the animals were removed from the 
smoke influence, a number of questions naturally suggest them¬ 
selves as worthy of consideration in order to establish con¬ 
clusively that the ulcers were the result of local arsenical action 
at the point where these lesions developed. These questions will 
