1894.] Oxygen upon the Coagulability of the Blood in Vivo. 285 



other hand, if the interpretation which we have placed upon the 

 results of our experiments on the effect of a diminution of oxygen is 

 correct, we should expect an increase of coagulability to accompany 

 the restoration of oxygen to the blood. 



The following is a summary of the results of the experiments which 

 were directed to the determination of this point. 



In a total of fourteen experiments, restoration of atmospheric air 

 was in ten instances* found to result in an increase of coagulability. 

 In the four remaining instances a decrease of coagulability was 

 noted. It is, however, significant that in two of these instances the 

 diminution of coagulability which was observed lay well within the 

 limits of error of the method of determination, while in the remaining 

 two instancesf the diminution of coagulability was only a rebound 

 from a condition of increased blood coagulability which was brought 

 about by an accidental obstruction to the expiration of carbonic acid. 



We may, therefore, conclude that the restoration of oxygen to 

 hcemic blood conditions an increase of coagulability. 



'omparison of the Results obtained above with the Results obtained by 

 }$>' other Observers. 



In recent times the question of the influence exerted by the blood 

 gases on coagulation has been investigated among others by 

 Vierordt,! Hasebroek, and Bonne, || and also by Mathieu and 

 Urbain.^f The two first of these observers employed Vierordt's 

 method of coagulability determinations, and both observers per- 

 formed their experiments chiefly upon themselves. In none of their 

 experiments does any attempt appear to have been made to dissociate 

 the effect of changes in the quantity of carbonic acid in the blood from 

 the effect of simultaneous changes in the quantity of oxygen in the 

 >d. On the contrary, the phenomena which came under observa- 

 on appear to have been referred to either one or other of these causes 

 according to the particular bias of either observer. Thus Vierordt 

 ascribes the increased coagulability which he detected in the stagnat- 

 g blood of his ligatured finger to an increase in the C0 2 tension. On 

 e other hand, Hasebroek, who reinvestigated this point, interprets 

 e increased coagulability which is observed after a brief appl wa- 

 tt of a ligature to the finger as an effect of a diminution of oxygen 



* Examples of such increase of coagulability are given on protocols of rabbit 175, 

 >g 4, rabbit 176, and rabbit 178. 



t Vide third coagulation-determination on protocol of dog 4 and penultimate 

 gulation-determination on protocol of rabbit 176. 

 J Loc. cit. 



' Zeit. f. Biol.,' 1882. 



' Ueber das Fibrin- Ferment," Wiirzburg, 1889. 

 ' Coinptes Bendus,' 1874, vol. 2, pp. 665 et seq., and 698 et teq. 





