7 o SCIENCE PROGRESS 



albumose, is the type — which exert specific action only when they 

 are introduced into the circulating blood. The reaction of the 

 organism, consequent upon intravenous injection, is essential, 

 in order that substances restraining coagulation shall arise. 



2. Substances which act independently and directly upon 

 blood both inside and outside the organism. 



Various animals react differently to peptone injection, and 

 individuals of the same species require various amounts of 

 peptone per kilogramme body-weight. To obtain blood which, 

 when shed, shall be completely incoagulable, the injection must 

 be made into the circulation with rapidity, and the animals 

 should be fasting. Contejean states that when peptone is 

 introduced into the peritoneal cavity it has no effect on the 

 coagulability of blood. Certain snake-poisons, thrombo-kinase, 

 or nucleo-protein, and the artificially synthesised celloids of 

 Grimaux, which give many of the colour reactions of protein 

 bodies, will all in various doses induce intra-vascular clotting. 

 Albino rabbits and the Norwegian hare in winter-time are 

 generally regarded as immune to an injection of the last two 

 bodies (Pickering), but, as E. H. Starling has pointed out, the 

 statement is inaccurate for albino animals. 



The injected peptone is a digestive product, obtained by the 

 action of trypsin. It is a mixture of albumoses and probably 

 other less-known substances. Pick and Spiro consider that 

 a heat-resistant body, peptozym, which is without influence 

 upon extra-vascular blood, is the essential agent which affects 

 intravascular plasma. The behaviour of peptone-plasma is 

 inconstant. It may clot after a time spontaneously, but may 

 do so quickly or not at all. Witte's peptone, in doses below 

 2 centigrammes per kilo body-weight, hastens coagulation, 

 but above this dose it exerts a retarding influence (W. M. 

 Thompson J ). Water, weak acetic acid, or a stream of carbon 

 dioxide, induces coagulation in peptone-plasma, even when this 

 is free from leucocytes (Wooldridge). From a mass of conflicting 

 statements it would appear that peptone-plasma contains throm- 

 bogen, kinase, and calcium ions, but no thrombin. It is probable 

 that, like normal plasma which contains some anti-thrombin, an 

 excess of this substance is present, and its development is due 

 to a reaction of the organism following the introduction of 

 peptozym. That anti-kinase is also present is doubtful, since 



1 Journal of Physiology, vol. xx. 1896. 



