378 



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



in ice and without delay these were centrifuged at 4° C, after which the tubes 

 were again surrounded by ice till required. By this method a clear fluid 

 mammalian plasma was obtained unaltered by foreign substances and which 

 had made but little, if any, progress towards coagulation. At the temperature 

 mentioned leucocytes do not exhibit amoeboid movement and it may be 

 assumed that all secretion by them is inhibited. To this plasma " peptone " 

 was added in concentrations varying from 0'3-l"2 per cent, of the total volume 

 of " peptone " and plasma and the mixture was observed at room temperature 

 in paraffined vessels. In all cases except one, the typical anticoagulant action 

 of " peptone " was evident. A study of the protocols shows that the results 

 are essentially the same as when " peptone " in similar concentration is either 

 added to shed blood at laboratory temperatures or is intra vascular ly injected 

 into whole animals or into animals where the liver is out of circulation. 

 Evidence is thus forthcoming that leucocytes play no 'part in the inhibition of 

 coagulation which follows the rapid admixture of blood and " peptone." 



\ Control 

 plasma 

 ! on 

 i paraffin. 



Control 

 plasma 



on 

 glass. 



-3 p.c. 

 peptone 

 plasma 



on 

 paraffin. 



-6 p.c. 

 peptone 

 plasma 



on 

 paraffin. 



-9 p.c. 

 peptone 

 plasma 



on 

 paraffin. 



-9 p.c. 

 peptone 

 plasma 



on 

 paraffin. 



Time of adding " peptone 



> 



/ // 







i // 

 











/ // 

 







Time of "commencement' 



of 



8 



5 



7 40 



12 5 



19 30 



16 



clotting 

















Time of " completion " 



of 



10 10 



8 20 



9 10 



54 50 



No end 



27 



clotting 













point 



17 











14 



15 



16 



Notes. 



Plasma obtained from animal respiring A.C.E. and air. 



J . In No. 16 clotting was not typical ; small clots were formed. 



2. In No. 17 the gelatinous clot appeared to liquefy after 29 minutes ; 10 minutes later all 

 was liquid except one small clot. Syneresis is not excluded. 



3. The residual fluids from 16 and 17 gave, next morning, no precipitate when fifth saturated 

 with ammonium sulphate. 



4. No. 14 is the only anomaly in a large number of observations. 



A comparison of Experiments 14-17 with Nos. 18-20 illustrates the 

 difference between the action of " peptone " on plasma from an animal under 

 complete anaesthesia (A. C. E.) and the action of similar quantities of 

 " peptone " on blood from a pithed animal 15 minutes after the discontinuance 

 of the anaesthetic. 



There is consistently less " peptone " inhibition of clotting when the 

 animal is under anaesthesia at the time the blood is obtained. Early in these 

 experiments it was evident that the shed blood of anaesthetised animals was 



