Transactions of the Canadian Institute. 



^ 



[Vol. VII. 



Tracing ^y is from a dog twenty-two pounds 

 in weight which had previously been given ^ 

 grain of morphia hypodermically. Some minutes 

 before this tracing begins he had been given 6 

 minims of nitrite of amy), but the effects of this 

 had completely worn off He was now given 

 three minims of Scheele's acid by the mouth, i.e., 

 about the maximum dose recommended by 

 Professor Hobday. In a few seconds, as shown 

 by the tracing, the respiration became very ample 

 and then hastened, the pulse somewhat increased 

 in speed and the pressure was a little raised. No 

 bad effects ensued. 



Next we come to a series of experiments 

 undertaken to find the effects of repeated doses 

 of H.C.N. 



Tracings 38, 39 and 40 are from the same dog 

 and show well the effects of repeated doses of the 

 drug. The dog was a fox terrier weighing about 

 twelve pounds. At 17, 3 minims of Scheele's 

 acid were placed on the back of the tongue. 

 Almost immediately the pulse hastened, the 

 respiration became greatly excited, irregular and 

 more ample, and the blood pressure rose somewhat. 

 A couple of minutes later, fifteen seconds before 

 tracing 39 begins, the dose was repeated. The 

 same effects occurred, but soon wore off, and at 

 1 8a the tracing looks as it did before the first dose 

 of H.C.N, was administered. Two minutes later 

 the dose was again repeated at 19 (in tracing 40). 

 The respiration once more became excited, but 

 soon grew infrequent, the pulse became much 

 slower and the pressure fell, making the chart look 

 like that from one form of asphyxia, and soon the 

 animal died of respiratory failure. The thorax 

 was quickly opened and the heart was seen to be 

 still beating — and it continued to beat even after 

 it was completely removed from the body ; and, 

 when the contractions had ceased, they could for 

 several minutes be started again by simply putting 



