CHEMICAL CONSTITUENTS OF ABNORMAL SECRETIONS. 77 



crystallizable, odourless, and tasteless organic fatty- 

 looking substance, composed in 100 parts of 

 Carbon . . 54'96 



Oxygen . . 2444 



Nitrogen . . 10-68 



Hydrogen . . 9'92 



100.00 



And although looking something like fatty matter, 

 yet it is quite different from it in its chemical reactions ; 

 for it is very soluble in water, strong acids, and alka- 

 lies, sparingly soluble in alcohol, and quite insoluble 

 in ether. 



In searching for Leucine, about half an ounce of 

 urine should be slowly evaporated to the consistency of 

 a syrup, set aside to cool, and afterwards examined 

 under the field of the microscope, when circular, oily- 

 looking discs, occasionally laminated like the granules 

 of potato starch, will be revealed to sight. The best 

 chemical test hitherto discovered is that proposed by 

 Scherer, and confirmed by Frerichs and Harley 

 namely, to put a small quantity of the urine on a 

 platinum spatula, add nitric acid, evaporate to dryness, 

 and then treat the residue with caustic soda, which 

 dissolves it. When the solution thus obtained is con- 

 centrated, an oily-looking drop is formed, which can be 

 readily rolled on the spatula. 



Physiologically. Leucine has for some years been 

 known to scientific men as a normal product of some of 

 the organs of the body ; and according to the researches 

 of Liebig, Scherer, Frerichs, Neukomm, and Harley, it 

 may now be said to be one of the normal constituents 



