54 PHYSIOLOGY AND TOXICOLOGY 



Action of Venom on Frogs. — This industrious and most able writer is also the only 

 one who has recorded the effects of the viper poison on frogs/ and, so far as I 

 am aware, no one has repeated these observations. It is to be regretted that he 

 did not state the size of the frogs bitten, since in such facts, or in the fresher 

 state of his snakes, might have been found the reasons why the frogs which were 

 subjected to the Crotalus venom, usually lived so much longer than those upon 

 which the learned Abbe experimented. In the total want of knowledge as to 

 the power of rattlesnake poison over frogs, I shall quote the passage from Fontana, 

 in which he relates the results he obtained when making use of viper poison. 



He says, " I procured fifty of the largest and strongest frogs I could meet with. 

 I had each of them bit by a viper, some in the thighs, others in the legs, back, head, ' 

 etc. Some of them died in less than half an hour, others in an hour, and others 

 again in two, three hours, or somewhat more. There were some again that were 

 not affected, whilst others that did not die became nevertheless swelled. There 

 were, likewise, others among them that fell into a languishing state, their hind legs 

 that had been bit, continuing very weak, and even paralytic. In some of them T 

 contented myself with introducing cautiously into a wound, made with a lancet at the 

 very instant, a drop of venom. These last, however, lived longer than those I had 

 bit ; neither of them, however, escaped. I constantly took the precaution to prevent 

 the venom I introduced into the wound being carried out by the blood that flowed 

 from it. Some of these frogs swelled very much, others but little, and others not 

 at all. The wounds of almost all of them were inflamed more or less. There were 

 some, however, that died very suddenly, without the smallest mark of inflamma- 

 tion. A short time after these animals had been either bit, or wounded and ven- 

 omed, the loss of their muscular force, as well as that of the motion of their 

 extremities, was very evident. When they were set at liberty they no longer 

 leaped, but dragged their legs and bodies along with great difficulty, and could 

 scarcely withdraw their thighs when they were pricked with a needle, of the pain 

 of which they seemed almost insensible. By degrees they became motionless and 

 paralytic in every part of the body, and after continuing a very short time in this 

 state died." 



With this exception, and a few further remarks by the same author, we are 

 without information as to the effect of viper venom upon the frog. 



Of the effects of Crotalus venom upon the same animal, we know as little, and, 

 so far as I am aware, only a single recorded experiment of this kind is to be found 

 in the writings of American authors f their only observations upon cold-blooded 

 reptiles having been made on the Crotalus itself, or other serpents. We shall now 

 proceed to study the details of the experiments which I have made upon- cold- 

 blooded animals. 



Upon classifying the cases before us, it will be discovered that they divide them- 



' Fontana on Poisons, Chapter VI. p. 31, vol. i. Translation ljy J. Skinner, London, HSIf. 

 ° A single observation by Ilarlan. 



