808 



An attempt to obtain a larger amount of' material from the intes- 

 tines of pigs and oxen did not yield the looked for resnh, though 

 here also the activity of the extracts was satisfactory. Meanwhile, 

 since by the method, thus far employed, the activity disappeared 

 almost entirely, I tried to obtain a purified condition by a simpler 

 method, viz. through extraction with various solvents that could 

 readily be removed. 



With a view to this we prepared an extract from five small 

 intestines of cats, the alcoholic solution was evaporated to approxi- 

 mate dryness and the residue was extracted first with ether and 

 then with chloroform. What remained out of solution was treated 

 with a little glacial acetic acid. After evaporating this solution the 

 remainder was dissolved in 5 cc. Tyrode-fluid and the activity of 

 these solutions was determined. 



It now appeared that the portion dissolved in acetic acid exhibited 

 a much stronger activity than could be expected in an extract not 

 subjected to a preliminary treatment. By heating with acetic acid, 

 or stronger still with acetic acid anhydride, the activity seemed to 

 be largely increased, in some cases five-hundred fold. After acetyl- 

 ating the extract of one small intestine V5000 P^i't could still be seen 

 to exert distinct influence, whereas of the primary extract 7io — Vn 

 was needed to obtain this result, I always availed myself of this 

 quality of the extracts in my further experiments to ascertain to 

 what extent the various precipitates and filtrates still contained part 

 of the active constituents. The large increase of activity after acetyl- 

 ating, in connection with the property of tlie looked for substance of 

 yielding precipitates with phosphotungstic acid and in alcoholic 

 solution with sublimate and with platinic-chloride, naturally led us to 

 suppose that cholin, or an analogous compound, might be the active 

 constituent of the extracts as it was well known that the physio- 

 logical effects of cholin are as a rule largely increased by acetylating.') 

 We, therefore, ascertained whether the effect of cholin upon the gut 

 is also increased by acetylating. This proved to be the case as, indeed, 

 Guggenheim and Löffler'') have also reported. 



We did, however, not succeed in isolating cholin in a pure con- 

 dition from extracts of cats' small intestinep, nor in making an 

 approximately quantitative deteimination of the amount of cholin 



1) Hunt and Taveau, Bull. No. 73 of the Hygienic Laboratory of the Public 

 Health and Marine Hospital Service Washington (1911). 



Dale, Proc. Physiol. Soc. Journ. of Physiol. Vol. 48. Ill (1914). 

 ') Guggenheim und Löffler, Bioch. Zeitschr. 72 819 (1916). 

 Id. id. Bioch. Zeitschr. 74. 208 (1916). 



