OF THE VEX OM OF TEE RATTLESNAKE. 81 



fuiK'tioiis, find as, moreover, it will beat longer, when cut out and suspended, than 

 it usually does when subjected in its normal situation to the influence of the venom, 

 it is diiiicult to avt)id the conclusion that it is more or less directly affected by it. 

 It seemed to me equall}- plain, however, that it was not owing to the arrest of the 

 heart that the animal died. In fact, the heart continued to act after some of the 

 principal nervous functions, such as reflex acts, were over, so that their loss was 

 not due to an arrested circulation. 



The study of the effect of venom on the hearts of warm-blooded animals was 

 one of still greater difficulty. This aro.se from the fact that their functions are 

 more closely related to one another, so that the cessation of respiration necessarily 

 leads to loss of cardiac power, and vice versa; since, however, the determination of 

 the question before us was essential to a proper study of the remedies for venom 

 poisoning, I felt forced to continue my researches in this direction, notwithstanding 

 the obstacles in my path. 



As in the frog, I began by a series of simple observations upon the changes in 

 the heart which were apparent to the eye. For this purpose, I opened the chests 

 of rabbits sufficiently to obtain a view of the heart, the action of which was sus- 

 tained during the experiment by artificial respiration. 



Experiment. — Small male rabbit; pulse 280; respiration 120. Struck at 12 

 o'clock, 32 minutes, in the right flank. The animal fell in two minutes. Artifi- 

 cial respiration was at once used, and, owing to want of caution, the right lung 

 was torn, and the diaphragm ruptured. The chest was then opened. The heart 

 was acting very rapidly, and pretty well up to the thirteenth minute, when its 

 rhythm became disturbed, the right and left cavities acting separately. The 

 respiration was continued, with brief intervals, up to the sixty-third minute, when 

 the auricles alone responded, and the observation terminated. 



Experiment. — Small black female rabbit. A string was placed under the trachea. 

 The heart beat too rapidly for numeration. Bitten thrice in the side by a small 

 snake at 6.15 P.M. Fourth minute, pupils contracting. Fifth minute, head 

 falling. Seventh minute, slight general convulsions ; respiration feeble and labor- 

 ing. Tenth minute, slight convulsions; pupils dilated. Twelfth minute, respira- 

 tion stopped, and a tube being placed in the trachea, regular artificial respiration 

 was accomplished while the chest was opened, and the heart exposed. At first, the 

 heart beat regularly, but not very strongly. At the eighteenth minute, its rhythm 

 became altered, two auricular contractions taking place during each ventricular act. 

 At the twenty-second minute, the organ was acting very feebly, the auricles alone 

 beating, and the respiration was therefore discontinued. 



Experiment. — Small male rabbit. In this case, the artificial respiration was 

 made before the natural movement was over, about forty-four minutes after the 

 bite was inflicted. No convulsions were observed. Although the artificial respira- 

 tion was admirably sustained, the rhythm of the heart became disturbed within 

 twelve minutes, the auricles beating twice as ftist as the ventricles. Before this 

 occurred, the heart acted well, except that it did not seem to possess the energy 

 which it usually does under other circumstances. 



Experiment. — Large male rabbit. The trachea was prepared as usual, except 

 11 



