56 THE VENOMS OF CERTAIN THANATOPHIDEJ3. 



CHAPTEK VII. 



THE ACTION OF VENOMS AND THEIR ISOLATED GLOBULINS AND 

 PEPTONES UPON THE PULSE-RATE. 



Section I. — Pure Venom. 



The experiments made in connection with the pulse-rate were performed upon 

 rabbits, and in every case, unless otherwise noted, the poison was dissolved in 1 

 c. c. of distilled water and injected intravenously, usually into the external jugular 

 vein. 



In researches made with the isolated poisons doses were usually employed 

 which represented the amount of the individual poison contained in the commonly 

 employed doses' of the pure dried venom, thus giving a fair idea of the part played 

 by the individual principles in the results produced. In some experiments, how- 

 ever, much larger doses were used to learn more fully the poisonous character 

 of these substances. 



In all of our observations we find that the results produced in animals, under 

 apparently the same conditions and by using the same doses, vary very greatly; 

 sometimes the pulse is quickened from the first and remains beyond the normal 

 until death ensues, sometimes there is a primary diminution followed by an 

 increase, at others there is a diminution which continues until death. The pulse 

 is generally found to vary much in frequency. These facts all suggest that the 

 action of the pure venom is of a complex nature; there being several factors con- 

 cerned in the various alterations, and render it not improbable that in some instances 

 ecchymoses in the various organs may account for exceptional variations. 



Twenty experiments were made with pure venoms upon normal animals ; six of 

 these were made with the venom of the Crotcdus adamanteus ; in three the pulse- 

 rate was diminished and remained below normal, in two there was a primary 

 increase followed by a diminution, and in one of these the pulse-rate afterwards went 

 above the normal, white in another there was a primary diminution followed by an 

 increase. Of two experiments made with the Crotalus horridus, in one there was 

 an increase which continued until death, and in the other an increase followed by 

 a diminution below the normal, this diminution in turn being followed by a rise 

 above the normal, which continued until approaching death. In two experiments 

 with the Ancistrodon piscivorus, in one there was an increase and in the other a 

 decrease. One experiment with the Ancistrodon contortrix gave an increase. In 

 one experiment with the Crotalophorus miliaris there was a decrease followed by 

 an increase. In one with the Daboia Eussellii, which was not a perfectly satis- 



