888 . Experiments 



Now the 10 cc. of carbonic acid will be dissolved again or will 

 be given off at once by the lungs; as for the 40 cc. of nitrogen, 

 which corresponds to what would be present in 50 cc. of air, we 

 know that although such a volume of air, injected suddenly into 

 a vein of the heart, can check the contractions of this organ, espe- 

 cially when this air is cold, one can, on the contrary, introduce 

 without harm into the circulatory channels much larger quantities 

 of air, if moderate and successive injections are made. 



Nysten" long ago demonstrated this fact; but since misapprehen- 

 sions on this point are still common, I think I should report a few 

 very convincing experiments in this connection: 



Experiment DLXXXII. February 24. Little dog, weighing 4 kilos, 

 sick. Injected into the jugular vein in 4 minutes 14 cc. of air. The 

 animal dies in 10 minutes. 



Bloody foam in the right heart and the pulmonary artery; no gas 

 in the left heart. 



Experiment DLXXX1II. July 25. Dog weighing 5 kilos. Outer 

 temperature 21°. 



At 3 o'clock, single injection -in the left femoral vein of 20 cc. 

 of air. 



Immediately the heart is heard to beat with the noise of a dry 

 sponge being squeezed under water. The animal ceases to breathe; 

 the heart seems to stop; the conjunctiva, but not the cornea, becomes 

 insensible. 



Then the respirations begin again, at first very rare and very 

 deep, then hasty. The heart sounds reappear, normal. 



3:15; new injection of 20 cc. Same phenomena, although less 

 pronounced: sensitivity, respiration, heart beats do not completely 

 disappear; stiff enings of the front legs; little cries. 



3:25; the animal seems quite recovered. Injection at one time of 

 40 cc. of air. Immediately stiffenings of the legs, heart sounds, respir- 

 atory difficulties; the whole condition becomes worse, and at 3:35 

 the heart can no longer be heard. 



Autopsy at 3:50. Right auricle and ventricle full of blood frothed 

 with air, with clots full of air; a little gas in the vena cava. No air 

 in the pulmonary arteries or the left heart. 



Experiment DLXXXIV. February 14. Bulldog weighing 12 kilos. 



Progressive injection in 9 minutes of 130 cc. of air, into the left 

 jugular vein. 



Seems rather uneasy during the injection, but released imme- 

 diately after, is in good condition. 



Experiment DLXXXV. February 24. Vigorous hunting dog, weigh- 

 ing 15.5 kilos. Outside temperature 14°. 



3:15. Every two minutes, an injection of 65 cc. of air in 30 seconds 

 into the right jugular vein, with an excellent glass syringe. 



At each injection the animal moans, and immediately, even at a 

 distance, the sounds of heart gurgles are heard. 



