370 



Drs. J. W. Pickering and J. A. Hewitt. 



Experiment No. 3. — Pithed cat. Aorta and inferior vena cava ligatured. 



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^ ' ^ I L_ ! i i i hk l i^i l i I J/ i 



5 /O /S 20 25 30 35 4-0 45 SO S5 60 65 70 75 <90 



Time of observation , minutes 



Experiment No. 4. — Cat, pithed. Artificial respiration. Aorta and inferior 

 vena cava ligatured. 1/625 grm. of " peptone " was injected rapidly into the 

 heart over a period of 4 minutes. Five minutes after the injection of the 

 " peptone," coagulation time showed a retardation of 20 minutes in commence- 

 ment of clotting, a complete gelatinous clot appearing 2 minutes 40 seconds 

 later. This apparently liquefied, but further clots appeared in the liquid 

 during the subsequent 2 hours, and the fluid was completely clotted on the 

 following morning. While all other results have been repeated, this is the 

 only occasion in these experiments where the phenomenon described in the 

 dog by Doyon has been observed. Other samples of blood from this animal 

 behaved similarly to those in Experiment No. 3, the increase in concentra- 

 tion of " peptone " used not causing any substantially greater inhibition than 

 was evident in No. 3. The passage of carbon dioxide through the peptone 

 blood from this animal gave typical clotting, as did dilution with distilled 

 water. 



The total time taken in No. 1 was 1 hour 10 minutes, in No. 2 1 hour 

 22 minutes, and, moreover, no anaesthetic was being respired. Hedon and 

 Delezenne's experiments occupied " some hours," while in Delezenne's 

 observation no less than 5 hours elapsed from the commencement of the 

 operation till the observation of the coagulation time of the peptone blood. 

 During these protracted periods a volatile anaesthetic was being administered 

 and no attention was paid to the effect of a possible increase of the concen- 

 tration of carbon dioxide in the circulation, under conditions liable to promote 



