American Poifon called Ticimas, xxvii 
has alfo fome fymptoms of the nervous diforders, and it ap- 
pears that the nerves are chiefly affedled, although experiments 
have determined the contrary : therefore, we ought here alfo to 
have recourfe to experiments, and not fuffer ourfelves to be fe- 
duced by an unfounded theory, and by fpecious reafonings> , 
To proceed methodically in this important queftion, I 
thought it would be proper to begin by examining whether the 
American poifon produces any lenlible alteration in the blood 
drawn from the veins of animals, when it is mixed with it. 
I cut off the head of a pigeon, and received its warm blood 
into two warm conical glafles, to the amount of about eighty 
drops into each. Into the one glafs I put four drops of water, 
and into the other four drops of the poifon, diflblved in water 
as ufual ; the quantity of poifon in thefe four drops fcarcely 
amounting to one grain in weight when dry. I ftirred round 
equally the contents of the two glafles for a few feconds, in 
order to mix the materials well together. In two minutes the 
blood which was mixed with the pure water was coagulated ; 
but the other blood which was united with the American poifon 
never coagulated, but became darker and blacker than the 
former, which remained red as ufual. Three hours after it was 
ftill as fluid as at firff, while in the other glafs the ferum appeared 
to be already feparated from the red part. 
I examined the blood of both the glafles with a microfcope, 
both at that time and afterwards, and found that the red glo- 
bules ftill preferved their original figure, and that there was no 
difference between the two in this refpech 
I repeated this experiment many times with the fame fuccefs ; 
fo that it is evident, that the American poifon does not fenfibly 
alter the red globules of the blood in the circumftance above 
mentioned. It is, however, worthy of obfervation, that this 
poifon is fo far from coagulating the blood, that it abfolutely 
prevents the coagulation which happens in the blood after it is 
drawn from animals ; yet it cannot be faid to attenuate or diffolve 
the blood, fince nothing of that kind is obferved when it is exa- 
mined with a microfcope, the red part remaining figured as in its 
D 2 natural 
