8 SCIENCE PROGRESS. 



Martin made most of his observations on dogs, but 

 obtained confirmatory results on other animals (cats and 

 rabbits). He found that different doses produced different 

 results. Immediately after the introduction of the venom 

 the coagulability of the blood increases ; and this increase 

 in the case of moderate or large doses (more than croooi 

 gramme per kilo, of body weight) culminates in intravascular 

 clotting of greater or less extent. The injection of smaller 

 doses produces a transient phase of increased coagulability, 

 but after two minutes this is succeeded by a "negative 

 phase " ; the blood drawn either fails to clot at all, or does 

 so only after the lapse of several hours. The thrombosis 

 occurs more readily in venous than arterial blood, and is 

 frequently confined to the portal area. 



These results show a great resemblance between the 

 action of the venom and that of tissue-fibroofen or nucleo- 

 albumin. The effect of diminished coagulability is not un- 

 expected, seeing that the principal substance in the venom 

 is albumose. But the minuteness of the dose necessary is 

 very striking and distinctive. 



The question arises, does the poison contain nucleo- 

 albumin ? A nucleo-albumin is a proteid united to a sub- 

 stance rich in phosphorus, called nuclein. It can be de- 

 tected by the fact that artificial gastric digestion dissolves 

 the proteid and leaves the nuclein as an insoluble residue. 

 This residue must then be examined for phosphorus. 

 Snake venom contains no nucleo-albumin ; and its action not 

 only opens up a novel aspect of the subject of snake poison- 

 ing, but also sheds light on the vexed problem of blood 

 coagulation. 



The smallness of the dose suggests that the injected 

 material does not contribute itself to fibrin formation. Pro- 

 bably it acts by producing disintegration of the cells in 

 proximity to the blood stream, such as the endothelial cells 

 lining the vascular system. If it thus liberates nucleo-albu- 

 min from these the conditions would be practically the same 

 as if this toxic agent were injected from without. The 

 venom is capable of playing havoc with these cells. This 

 was originally shown by Weir Mitchell and Reichert. These 



