372 Mr. S. B. Schryver. Investigations dealing with the 



Polyhydroxy-Derivatives. 



The inhibitory action of these substances is small, as is shown by the 

 following examples : — 



Substance. 



Per cent, (weight). 



Clotting time, sees. 



Ethylene glycol 



12 -5 



281 



Propylene „ 



8 -75 



385 







(with separation of crystals) 



Glycerol 



12 5 



148 





12-5 



29 





12 -5 



30 





12 -5 



258 





10 -o 



100 



Discussion of Results. 



Whilst it cannot be denied that those substances which lower most 

 markedly the surface tension of water have, as a rule, the greatest tendency 

 to exert an inhibitory effect on the formation of the cholate gel, the law is 

 not by any means an absolute one. The exceptions are precisely the ones 

 which deviate from Czapek's generalisation. Acetonitrile, which lowers the 

 surface tension of water but little, has a greater inhibitory power than ethyl 

 alcohol, which lowers it much more. The deviation from the rule is shown 

 in a very marked manner also by the typical narcotics, chloral, chloroform, 

 and (in the experiment on gel formation) by urethane. There is, in fact, a 

 striking parallelism between inhibition of gel formation, narcotic and 

 haemolytic actions and production of tannin exosmosis, which is well 

 exhibited in the following table. The various substances are arranged 



Substances in decreasing order of 

 gel-inhibiting action. 



Critical narcotic concentration. 

 Grm. mol. per litre. 



Chloroform 



-0012 



Chloralhydrate 



. 0-02 



Isoamyl alcohol 



0-023 



Secondary amyl alcohol (methyl propyl carbinol) 







0-037 



Propyl carbaminate 





Normal butyl alcohol 



0-038 



(Methvl propyl ketone 



-019) 



Isobutyl alcohol 



045 



Normal propyl alcohol 



o-ii 



Urethane 



0-041 



Tertiary butyl alcohol 



0-13 



Isopropyl alcohol 



0-13 



Allyl alcohol 



0-13 





0-27 



Acetonitrile 



36 



Ethyl alcohol 



3 



