The Action of " Peptone" on Blood and Immunity thereto. 373 



been impossible to investigate any relationship to hydrion concentration of 

 this transient but significant phenomenon. 



The earlier observations on the effect of the injection of " peptone " into 

 animals with either impaired or partly excised livers, have formed the basis 

 for a vast superstructure of hypotheses. They remain crucial only so long- 

 as the anticoagulant action of " peptone " has not been observed in animals 

 when the liver is not acting. 



Employing a somewhat simpler operative technique to deprive the liver 

 of circulating blood with a view of avoiding the prolonged interval before 

 the injection of " peptone " (with the consequent accumulation of carbon 

 dioxide), the results given in experiments, Nos. 2, 3 and 4 above, 

 demonstrate decisively that retardation of coagulation of blood consequent to 

 the rapid intravascular injection of moderate amounts of " peptone " can be 

 ^produced under conditions vjhich preclude the participation of the liver. 



Stress is laid on the importance of working with pithed animals, and in 

 allowing at least 15 minutes to elapse after pithing and the discontinuance 

 of the anaesthetic before the injection of " peptone," so that any action 

 of the anaesthetic on the coagulability of the blood may be eliminated. It is 

 also advisable to regulate the air supply to the animals so as to maintain, as 

 long as possible, normal oxygenation. 



On the action of "peptone" on blood in vitro. 



The well known observation of Schmidt-Mulheim (32) that very large 

 quantities of " peptone " are necessary to retard the coagulation of blood 

 in vitro is commonly regarded as showing that " peptone " has no specific 

 action on shed blood. Among the earlier observers, Afanassiew (33), 

 however, stated that blood shed direct from the artery of a dog, without 

 exposure to the air, into 1*225 — 1*5 per cent. " peptone," and kept at 

 40°, remained fluid. Unfortunately the details of the experiment are 

 meagre. Pollitzer (34) stated that 2 per cent, of heteroalbumose inhibited 

 blood clotting in vitro, while Halliburton (35) recorded that the same 

 substance also delayed the coagulation of salted plasma. Working with 

 lymph from the thoracic duct which clotted, at room temperature, in from 

 10 to 15 minutes, Shore (36) found that when relatively large quantities of 

 " peptone " were added in vitro the clotting was as rapid as in pure shed 

 lymph, but if smaller amounts of " peptone " were used retardation occurred. 

 In one experiment in which the amount of " peptone " was - 0377 per cent., 

 the lymph remained fluid for 24 hours. 



Camus and Gley (37) reinvestigated the effect of adding " peptone " to 

 shed blood, and stated that from eleven to fifteen times more " peptone " is 



