Phenomena of " Clot " Formations. 369 



the concentration of that substance which will produce exosmosis. The 

 conceptions of Czapek have been subjected to severe criticism, principally by 

 Vernon, who has shown that there are many exceptions to Czapek's rule. 

 Several substances, especially the narcotics and acetonitrile, produce 

 exosmosis in solutions, the surface tensions of which are appreciably greater 

 than Czapek's critical point. Czapek accounts for the exceptions to his rule 

 by ascribing to them some specific toxic property. 



Vernon has shown that a marked parallelism exists between haemolytie 

 and narcotic actions and the inhibitory action on indophenol oxydases of 

 animal tissues. Batelli and Mile. Stern support Vernon's views in their 

 investigations on the so-called oxydones and correlate the various toxic 

 properties with the property of precipitating nucleoproteins.* 



In view of the above-mentioned facts and the preliminary experience 

 obtained from the study of the calcium salts as to the action of surface 

 tensions, it was a matter of considerable interest to study the inhibitory 

 action of various organic substances on the formation of the cholate gel, which 

 is derived from chemically pure crystalline products, and which, in thin films, 

 might be regarded as a structure analogous to the cell membranes. As 

 a result it was found that whilst generally those substances which have the 

 greatest power in lowering the surface tension of water have a greater 

 inhibitory action on the gel formation, this rule is by no means absolute, 

 and the chief exceptions are the narcotics and acetonitrile, i.e. the very 

 substances which deviate from Czapek's generalisation. There is, moreover, 

 a very close parallelism between the inhibitory action on gel formation and 

 narcotic and other biological reactions. In the following experiments 

 - 5 c.c. of calcium chloride was diluted to 3 c.c. with water containing a 

 given amount of the substance under investigation, and this was then mixed 

 with 1 c.c. of 4-per-cent. sodium cholate, and the clotting time was deter- 

 mined by the method given above. The concentration of cholate in the 

 mixture was, therefore, 1 per cent., and of the calcium chloride, N/8. By 

 determining the weights as well as the volumes of the organic substances," 

 and also the specific gravity of the solutions, the concentrations in gramme 

 molecules per litre could be calculated. 



* 'Biochem. Zeitsch.,' vol. 51, p. 1 (1913). 



