Scientific Proceedings. 



(127) 63 



with the vascular supply of the kidney. Consequently, the blood- 

 pressure conditions can be accurately transmitted to a recording 

 instrument. The question then arises, why use an oncometer to 

 obtain records of blood-pressure conditions in the kidney ? 



10. May not the diuretic effect, which is noted after adminis- 

 tration of small doses of such drugs as mercury, 1 for example, be 

 attributed, in part at least, to the increased peristalsis of the ureter, 

 causing, as it does, an increased negative pressure and therefore 

 an increased filtration ? 



29 (75). " Further observations upon the phosphorized fats in 

 extracts of the kidney ": EDWARD K. DUNHAM. (Pre- 

 sented by PHGBBUS A. LEVENE.) 



Last winter, at a meeting of this society (Proceedings, Vol. I, 

 page 39), the author reported observations showing that extracts 

 from dried kidneys, obtained with the Rosenfeld alcohol-chloroform 

 method, contained from a third to two-thirds of their weights of 

 lecithins. Rubow, 2 of Copenhagen, reported similar results of more 

 extended studies, printed in Danish some months earlier. 



During the last few months the author has learned that it is not 

 necessary to boil with absolute alcohol and extract with chloroform 

 in order to obtain the large quantities of extract yielded by the 

 Rosenfeld method. Repeated extraction of the fresh, undried 

 organ, with 8$fo alcohol at 45 0 C, will accomplish practically the 

 same result. When making these extracts, it was found that upon 

 cooling, the alcoholic solutions yielded a precipitate from which a 

 substance resembling the protagon of Liebreich could be obtained. 

 It is to this substance that the author directs attention in this report. 

 The yield is from about o. 14^ to o.2ofo of the fresh organ, or from 

 about o.6fo to 1. of) of the dried kidney. 



In order to obtain sufficient material for analysis, the author 

 employed the method used by Cramer 3 in preparing protagon 

 from the brain. The method employed was, in brief, as follows : 

 The minced kidney, freed from obvious fat, was treated twice with 

 Sfo sodium sulfate solution at 85 0 C. to 90 0 C. ; the filtrates were 

 discarded and the coagulum extracted, first with g$fo alcohol and 



1 Cushny : A textbook of pharmacology and therapeutics, 1901, p. 623. 



2 Rubow : Archiv fur experimentelle Pathologie und Pharmacologie, 1904, lii, 

 P- 173- 



3 Cramer : Journal of Physiology, 1904, xxxi, p. 31. 



