THE PTOMAINS OF THE URINE. 299 



Gases. 



In normal urine a certain amount of oxygen, nitrogen, and nota- 

 bly of carbon dioxide is found in solution, and can be withdrawn 

 by the air-pump. Under pathological conditions, further, a variable 

 amount of hydrogen sulphide may be encountered. This notably 

 occurs in cases of cystitis, in which the decomposition of albumin 

 and sulphur bodies may already take place within the bladder, owing 

 to the activity of various micro-organisms. But in a few isolated 

 cases the gas was apparently derived from the intestinal tract, and 

 absorbed either directly from the rectum or indirectly from the 

 blood. 



All urines when exposed to the air sooner or later contain hydro- 

 gen sulphide in the free state, which is referable, as stated above, 

 to the action of certain micro-organisms. Especially large amounts 

 are observed when cystin-containing urines are thus allowed to 

 undergo decomposition. To test for hydrogen sulphide, a strip of 

 filter-paper is moistened with a few drops of a solution of sodium 

 hydrate and one of lead acetate, and is then clamped in the 

 neck of the bottle containing the urine. If the gas in question is 

 present, the paper is colored a grayish brown or black, owing to 

 the formation of lead sulphide. When present in large amounts 

 it is detected also by its odor. 



Ptomains. 



So far as known, ptomains are not found in the urine under 

 normal conditions. In disease, however, various basic substances 

 have been encountered which supposedly belong to this class. But 

 with the exception of cadaverin and putrescin, which, as has been 

 stated, may occur in association with cystinuria, these bodies have 

 been isolated in amounts scarcely sufficient to establish their 

 chemical nature. This holds good more especially of the bodies 

 which Griffith claims to have isolated from the urine of patients 

 suffering from scarlatina, measles, mumps, carcinoma, etc. 



As regards the- origin of putrescin and cadaverin in cystinuria, the 

 opinion prevails that they are due to a specific form of intestinal 

 putrefaction. This is, however, not necessarily the case, and in my 

 opinion the diaminuria, like the cystinuria, is the expression of a 

 distinct metabolic disturbance. I have pointed out that both diamins 

 can be derived from arginin and lysin in the laboratory, and there 

 is every reason to suppose that the same transformation can also 

 occur in the living organism. That arginin at least actually occurs 

 in the tissues of the body has been demonstrated by Gule witch, who 

 found the substance in the spleen. 



The quantity of the diamins which may be eliminated in the 

 urine in cases of cystinuria is quite variable. On some days traces 

 only or none at all is found, while at other times very considerable 

 amounts may be obtained. In one of my cases I was able to isolate 



