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



until a solution neutral to neutral red was obtained. An approximately 

 4-per-cent. solution was obtained. It was found, however, that cholalic acid 

 is soluble in sodium cholate solution, the amount dissolving varying with the 

 temperature. As this free acid inhibits the clotting, it was found that the 

 clotting time of a solution varied from day to day. For all subsequent 

 experiments, sodium cholate was prepared and a 4-per-cent. solution was made 

 directly from this. The cholate was made by dissolving cholalic acid in 20 

 times its weight of alcohol, neutralising this solution with sodium ethoxide, 

 heating for a short time on a water-bath and filtering off the first separation 

 of solid, and then evaporating the filtrate. Sodium cholate rapidly separated 

 after a short time, and was filtered off, washed with acetone, and then dried, 

 first on a water-bath, and then over sulphuric acid in a desiccator. It gave a 

 solution in water, acid to phenolphthalein, but slightly alkaline to neutral red. 



Table I. — Clotting Time of 1-per-cent. Sodium Cholate Solution (in seconds) 

 in presence of Varying Concentrations of different Calcium Salts. 





3N/4. 



N/2. 



3N/8. 



N/4. . 



N/8. 





3 



14 



14-0 



21 



34 



Bromide 



10 -5 



14 



15 -5 



21 



47 





16 



17 



37 -0 



40 



62 





18 -0 



17 



20-0 



24 



41 



Sulphocyanide 



87 o 



54 



47 



47 



70 



Formate 



11 -o 



14 



14 -0 



19 



38 



Acetate 



8-0 



10 



12 -0 



19 



34 





24 -0 



26 



33 -0 



36 



77 



Dichloracetate 



97 -0 



47 



33 -0 



30 



52 



Trichloracetate 



ep 



Incomplete clot in 



710 -0 



170 



122 







25 minutes 









Influence of Organic Compounds on the Gel Formation. 

 Many attempts have been made within recent years to correlate physical 

 properties of organic substances with their different biological actions, such as 

 the production of exosmosis, haemolysis, narcosis, etc. ; more especially, their 

 effect on the surface tension of water has been stated to be intimately 

 associated with the production of changes in the cell. Czapek* (in his 

 monograph, January, 1911) claims to have determined the surface tension 

 of the membrane of certain plant cells by showing that exosmosis of tannin 

 takes place, whenever they are immersed in solutions the surface tension of 

 which falls below 0681 (water = 1). The smaller the amount of a given 

 substance necessary to reduce the surface tension to this figure, the lower is 



* See also the numerous papers by Traube. 



