THE EFFECTS OF VENOM. 45 



membrane preserved its natural tint. On the side in which was the poison the 

 mucous membrane was wrinkled and raised in points like the surface of a mul- 

 berry. By stretching the mucous membrane this roughness disappeared. After 

 death it increased somewhat. There was no cedema. 



Experiment. — 0.01 gram of dried Cobra dissolved in a little water was given to 

 a frog by an oesophageal tube as in the case of the pigeons. .The frog presented 

 no toxic symptoms for two hours. After twelve hours it was dead. 



Autopsy. — All the tissues had a cyanotic appearance and the animal was perfectly 

 flaccid. The heart was still irritable as well as the intestines. The stomach con- 

 tained a viscid mass of mucus, which was not bloody, and which was expelled from 

 the stomach by the normal contractility when the organ was cut. A most careful 

 examination of the mouth, gullet, and mucous membrane of the stomach did not 

 reveal any abrasions or other raw surface. The liver seemed pale and decidedly 

 friable. 



In Dr. Mitchell's former experiments made in the opened crop, fatal results did 

 not occur with use of fresh or dry venom of Crotali ; but a single needle pricked 

 through the mucous surface covered by the poison, sufficed to let in death. 



It seems possible that minute ulcers or abrasions, quite invisible to the eye, 

 might, in like manner, enable the venom in some cases to pass the barrier of the 

 intestinal mucous lining. The deaths from ingested Cobra venom related by 

 Fayrer took place in mammals, and we ourselves found in like experiments with 

 rabbits, that, although death was rare after swallowing Cobra venom, it was less so 

 than in pigeons; but our Cobra experiments are not strictly comparable with those 

 done in India with fresh poison. 



Certainly Cobra venom is much more apt to kill when swallowed than is Cro- 

 talus poison. In the rattlesnake it is the globulins which are in largest amount, 

 and which are not dialysable, but in Cobra the fatal peptone is the material which, 

 both as to vigor and amount, represents the poisoning capacity, and is as we know 

 dialysable. It is only astonishing, therefore, that it does not kill in every case in 

 which it is swallowed; but, as we have seen, the gastric juices in so far as they 

 have time to act are destructive of venoms, and hence their protective agency has 

 also to be considered. 



The Activity of Venom when applied to Serous Surfaces. — One of the most 

 remarkable and interesting of the physiological effects produced by the venom of 

 the Crotalus is the occurrence of ecchymoses, especially in the serous tissues. The 

 character of these ecchymoses is fully treated in another part of the work, so that 

 we need here only detail some of our observations in connection with the direct 

 effect of the application of venom to the serous tissues. 



A rabbit was etherized and kept in this condition during the whole of the 

 experiment. The abdominal cavity was opened and a knuckle of intestine 

 exposed. On the peritoneum were placed a few small particles of the dried 

 venom of the Crotalus adamanteus. In two or three minutes some extravasations 

 appeared immediately about the point of the application of the venom; a few 

 moments later these extravasations were diffused over a considerable area and had 

 run into each other to such an extent as to form a patch of bleeding surface. So 



