EFFECT ON CIRCULATION AND RESPIRATION. 



351 



one limb of which was attached a stopcock, which allowed of 

 more or less free communication with the atmosphere and the 

 other limb of which was in connection with one of Marey's 

 cardiographic levers which registered the respirations on a 

 revolving cylinder. By increasing or diminishing the resistance 

 which the stopcock opposed to the entrance of air into the 

 tracheal cannula the amplitude of the excursions of the lever 

 could be altered at will. 



The blood-pressure was registered by a kymographion con- 

 nected with a cannula in the left carotid of the rabbit. The 

 number of cardiac pulsations was estimated from the undula- 

 tions produced by them in the blood-pressure tracings. 



Time. 



Eespi- 

 rations. 



Eemarks. 



abt. 4''. 15' 



abt. 4\ 23' 



4'". 32' 



5^ — 



in millimetres 



of mercury. 



120 



120 



120 



114 



108 



21 



18 



17 



20 



? 



in7i' 

 6f 



6^ 



6k 



7 



Each 6th respiration became larger 

 than the others when the injec- 

 tion was made. 



5 cub. cent, of a suspension of 

 4 grammes extract in water was 

 injected into the peritoneal 

 cavity. 



The respirations decame deeper and 

 the undulation in the tracing of 

 the blood-pressure corresponding 

 to every 6th respiration becomes 

 very distinct, while previously it 

 was very slight. 



This seems due to the pain of the 

 injection and the excitement of 

 the animal after it. 



Injected about 2| cub. cent. more. 

 The undulations in tlie pressure 

 curve again became more distinct 

 and the I'cspii atious much moi'e 

 forced. 



Attempted to inject more solution 

 into the peritoneum, but the tube 

 seemed stopped up and the solu- 

 tion would not enter. A clot 

 now formed in the cannula in the 

 carotid, so it was cleaned out. In 

 order to prevent the blood from 



