xxviii Abbe FONTANA on the 
natural ftate, and nothing more fubtle or more thin being 
obfervable in that fluid. 
A circumftance perfe&ly fimilar I alfo obferved to happen 
with the poifon of the viper ; fo that the effects or alterations 
caufed by thefe two poifon s in the blood drawn from the veflels, 
appear to be perfectly fimilar, both of them hindering the blood 
from coagulating, yet neither of them diflblving or altering the 
globules of it : the only difference between them is, that the 
poifon of the viper tinges the blood much blacker than the 
American poifon does. 
The poifon of the viper does not alter the globules of the 
blood even when it is given to the living animal, and that the 
animal in confequence dies. I have obferved the fame thing 
with refpect to thofe animals which are killed by the American 
poifon ; fo that the two poifon s agree in a wonderful manner in 
all thefe cafes. But as the poifon of the viper produces in ge- 
neral a fenfible alteration in the mafs of the blood of thofe ani- 
mals that are bit by it ; I thought that the fame attention ought 
to be paid to the examination of the blood of thofe animals 
which have died of the American poifon. 
I have obferved in general, that the mufcles of animals killed 
by the American poifon were paler than before ; the blood vef- 
. fels near the heart appeared more turgid than ufual ; the blood 
a little darker coloured than ordinary, though not much, nor 
coagulated ; the vifcera of the abdomen not fenfibly affedted ; 
the heart and the auricles in the natural ftate, although the 
heart had fometimes its external veflels more vifible, and that 
they appeared as if they were injedted. 
But I have obferved a great alteration in one of the vifcera, 
the moft eflential to life, to wit, the lungs, which always appeared 
greatly affedled. I have generally found them fpotted more or 
lefs ; often with large and livid fpots, and fometimes thejr 
feemed to be quite putrified. This effect on a vifcus fo eflen- 
tial to life deferves the greatefi; attention : it appeared to me, 
that it was the greater the longer the animal had lived after 
being poifoned. I have obferved the lungs of fome animals to 
4 be 
