CHAPTER XXII. 
EFFECTS OF SNAKE VENOM ON MUCOUS, CONJUNCTIVAL, AND 
SEROUS MEMBRANES AND THE ALIMENTARY TRACT. 
Weir Mitchell has shown that crotalus venom can be ingested by the pigeon, 
one of the most susceptible animals to this venom, with impunity, and no 
poisonous principle is recoverable from the excreta of the pigeon. Naturally 
this may depend upon two possibilities: the non-absorption of the venom 
through the buccal mucous membrane and the destructive action of the 
gastric and intestinal ferments. 
Mitchell and Reichert applied venom directly to the gastric membrane 
under laparotomy and found no visible changes produced by a few hours’ 
contact. This they ascribed to the non-absorption of the venom by unbroken 
mucous membrane. Here they did not pay attention to the inactivating 
action of hydrochloric acid —even in a very dilute concentration — upon 
the hemorrhagin of the venom; hence their conclusion regarding this particu- 
lar phenomenon may require some modification. 
The recent investigation of Ishizaka on the production of active immunity 
through oral administration of lachesis venom lends color to the occurrence 
of the absorption of that venom from the intestinal canal.’ 
Lacerda, Calmette, and C. J. Martin state that the venoms of Lachesis 
lanceolatus and Pseudechis may cause intense inflammation and hemorrhagic 
changes in the alimentary tract when sufficient quantities of these venoms 
are given by the mouth. If the dosage be sufficiently large death usually 
follows their administration, with the usual venom-poisoning symptoms. 
With the venom of cobra alimentary administration gives somewhat dif- 
ferent results from those obtained in the case of crotaline venoms. Brunton 
and Fayrer observed that fatal effect is produced in animals when cobra 
venom is given from the digestive tract by feeding. 
Fraser points out that absorption of cobra venom from the stomach is very 
slight. In rats and cats nearly 1,000 times the subcutaneous lethal dose 
was given without fatal effect. As a result of such administration of venom 
the serum of these animals was found to contain a certain amount of antitoxin. 
Calmette failed to confirm Fraser’s experiments, as he always found the 
venom to act fatally when given by the mouth in large dosage. 
Kanthack fully confirms Fraser’s observations that immunity can be secured 
by feeding the venom to animals. 
Briot and Massol have seen that cobra venom is more rapidly absorbed 
from the rectum of animals than from the areolar tissue of the skin. The 
1The absorbtion of foreign proteins through the alimentary tract has been recently demonstrated by 
Rosenau and Anderson by anaphylactic phenomena. 
220 
