PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 149 
dilute saline solution. The extract which contained some 
proteid’was quite harmless when injected under the skin of 
frogs and mice. 
If any quantity of the venom had been absorbed by the rats 
from the amount contained in their meals, they must have shown 
symptoms, and had the fceces contained any of the venom, symptoms 
of poisoning would have occured in the small animals injected 
with the last saline extract, for Psewdechis venom is unaltered by 
sojourn under absolute alcohol. Accordingly, one must conclude 
that the venom was either not absorbed, or if so only to a small 
extent, and that the greater part was destroyed in the alimentary : 
canal. The venom is destroyed by artificial pancreatic digestion, 
and that the same happens in the intestine is extremely probable. 
The toxic properties of this venom are however not destroyed by 
artificial gastric digestion, and the results of the experiments on 
the rats show that the poison exists in the stomach in an active 
| condition. The walls of this organ are lined by a continuous 
‘ layer of living epithelium cells, and cannot be reckoned with as 
if they were composed of a dead membrane. Indeed there is 
abundant evidence to show that in the process of absorption from 
the alimentary canal physical processes (osmosis, diffusion) are 
overborne by physiological ones,! and that the lining cells exere ise 
4 selective control over the process of absorption.? The toxic 
_ Proteids of some of the infectious diseases also, are not absorbed 
from the alimentary canal, for Tizzoni has shown that the most 
“irulent tetanus toxines produce no ill effects when administer ed 
by the mouth, Absorption does however probably occur to 4 
Small extent, for the remaining white rat, was after the lapse of 
5 week, injected with one and a half times a lethal dose of venom, 
— Jenaische Zeitschrift, Bd. xviii, 1885; Rohmann, 
hi. 1894 v., Bd. xli. 1887; Heidenhain, ibid., Bd. xliii., 1888; Bd. 
2 ‘ ‘hes 
Tappeiner, Wien. Sitzungsberichte, Bd. Ixxvii., Abtheil. iii., 1878; 
edkins, Journ. of Physiol., x1r., 1892; v. Mehring, Ver —— 
Congress £. imnere Med. z. Wiesbaden, 1893, p. 471. 
