1867.] 



On a Crystalline Fatty Acid from Urine. 



135 



which may serve to explam the fact of the existence of indican in urine 

 having so frequently been overlooked. 



From the experiments hitherto described, I am justified, I think, in 

 drawing the following conclusions : — 



1. Human urine contains, under all circumstances, two distinct and 

 peculiar extractive matters, one of which is soluble in alcohol and ether, 

 while the other is soluble in alcohol but insoluble in ether. 



2. The composition of these bodies is almost always the same, the slight 

 variations which are found to occur being due, not to any difference in the 

 quality or source of the urine employed at various tim.es, but rather to the 

 decomposition which takes place during the process of preparation, and 

 which cannot be entirely avoided. 



3. Both substances contain nitrogen as an essential constituent, but in 

 so small a proportion as to show that their atomic weight must be very 

 high. 



4. Both substances have a tendency to take up water, especially when 

 their aqueous solutions are heated or mixed with strong acids. 



b. The extractive matter insoluble in ether takes up a certain proportion 

 of oxygen, and is converted into a product, which does not differ in its 

 appearance or its most obvious physical properties from the original 

 substance. 



6. There exists no urinary extractive matter insoluble in alcohol, the 

 substance hitherto so called consisting in most cases of compounds of one 

 of the true extractive matters with various bases. 



III. On a Crystalline Fatty Acid from Human Urine.^^ By Edward 

 ScHUNCK_, F.R.S. Eeceived September 21, 1866"^. 



The occurrence of fatty matter in urine is a somewhat rare phenomenon, 

 and is generally considered as a symptom of disease, or at least of an 

 abnormal state of the system. In most cases it is found associated with 

 albumen, forming the so-called " chylous urine," in vv^hich the fatty matter 

 is suspended in such extremely minute particles as to give the liquid the 

 appearance of milk. In a few instances it has occurred in the shape of 

 fluid oil-globules floating about in the urine ; but it is more frequently 

 foLU'id enclosed in cells, which sink and form a deposit at the bottom of the 

 vessel. Fatty matter is a constituent of Jdesteine, the pellicle which is 

 sometimes formed on the surface of the urine of pregnant women ; and a 

 fat resembling butter was obtained from it by Lehmann, though by some 

 authors the very existence of kiesteine as a peculiar deposit is doubted. 

 Lastly, a few cases are described in which a fat-like substance was passed 

 with the urine in the form of small concretions, which, when fresh, were 

 soft and elastic, but dried into hard, yellow, wax-like masses (Heller's 



Kead November 15, 186G : sec Abstract, vol. xv. p. 258, 



