286 THE URINE. 



Ignatowski found glycocoll constantly in the urine of 7 gouty 

 patients ; in 3 of these also ammo-acids, probably leucin and 

 asparaginic acid. In pneumonia, especially about the time of the 

 crisis, and in leukaemia he likewise obtained positive results. 



In this connection the observations of Herter, Wakeman, and 

 Baldwin are of special interest. Using the method of Magnus- 

 Levy of balancing the total bases against the total known acids, 

 they found that in certain conditions, notably dilatation of the 

 stomach, rheumatoid arthritis, and cirrhosis of the liver, there was a 

 notable excess of bases over known acid equivalents. This leads to 

 the inference that in the diseases mentioned there must have been 

 present some other organic acids. Magnus-Levy had in this man- 

 ner previously established the presence of such acids in starvation, 

 in intestinal disturbances, phosphorus poisoning, acute yellow 

 atrophy, and fever. 



I append a few of Baldwin's results : 



APPARENT EXCESS OF ACIDS OVER BASES. 



Average of 10 normal urines 0.2943 



Average in diabetes mellitus 2.96 



Average in rheumatoid arthritis (active stage) 0.7347 



Average in " u " 0.5598 



Average in " " " 0.6783 



Average in " " " 0.6456 



Average in (case 16) . . . 0.8377 



Isolation. If leucin and tyrosin are present in the urine in small 

 amounts, they are held in solution. In the presence of larger 

 amounts the tyrosin may separate out, and can then be isolated from 

 the sediment and identified as described. Leucin, however, is rarely 

 found in this manner, and remains in solution even though very 

 large quantities are eliminated. 



To demonstrate both when they are held in solution, it is some- 

 times only necessary to concentrate a small amount of urine on a 

 water-bath and to examine the residual syrup with the microscope. 

 Otherwise it is advisable to precipitate the collected urine of 

 twenty-four hours, after removing any albumin that may be present, 

 with basic lead acetate. The filtrate is then freed from lead with 

 hydrogen sulphide, evaporated to a thick syrup, and set aside for 

 crystallization. Tyrosin and leucin can then be demonstrated by a 

 microscopical examination and identified in the usual manner (see 

 page 207). 



THE NEUTRAL SULPHUR BODIES OF THE URINE. 



In the section on the mineral constituents of the urine I pointed 

 out that the greater portion of the sulphur which is set free during 

 the metabolism of the nitrogenous constituents of the body is elimi- 

 nated in the urine in a completely oxidized form. A much smaller 

 fraction, however, escapes oxidation, and appears in the urine as 



