340 COLLOIDS IN BIOLOGY AND MEDICINE 



renal disease, and that the molecular concentration of the urine of 

 nephritics approaches the molecular concentration of the blood. A 

 table from the paper of A. VON KORAN YI, KOVESI and ROTH-SCHULTZ* 

 explains this: 



FREEZING POINT DEPRESSION. 



A. GALLEOTTI* obtained from dogs suffering from phosphorus and 

 sublimate nephritis, a urine with a freezing point depression practi- 

 cally identical with that of the blood; PH. BOTTAZZI and ONORATO* 

 obtained it likewise from dogs poisoned with sodium fluorid. An 

 experiment by these authors with a dog suffering from cantharides 

 nephritis is, however, especially instructive; in this case the urinifer- 

 ous tubules are practically unchanged and, accordingly, their activity 

 in concentrating the urine is practically uninfluenced. 



If a healthy person drinks water freely, there results a markedly 

 increased flow of urine, which in the case of nephritics does not 

 occur. KOVESI and G. ILLYES examined the urine obtained through 

 ureteral catheters from persons who had a healthy and a diseased 

 kidney. When a great deal of water had been drunk, there was se- 

 creted from the healthy kidney a large quantity of very dilute urine, 

 while from the diseased kidney, urine of average concentration was ob- 

 tained. Since both kidneys received the same blood, the blood could 

 not have been responsible for the more dilute filtrate, but the subse- 

 quent dilution must have been omitted by the kidney with the im- 

 paired function. In a diseased kidney, not only does the concentration 

 of the urine approach that of the blood, but even the amount of the 

 individual crystalloids contained becomes similar to that of an 

 ultrafiltrate from the blood. There are very few investigations on 

 this subject and they are chiefly limited to the chlorids. Some data 

 supplied by ALBARRAN warrant our conclusion. We saw on page 335 

 that there is approximately twelve times as much NaCl as urea in 

 the blood, whereas in the urine there is about one-half as much NaCl 

 as urea. Whenever the kidney parenchyma is much diseased, the 

 urea content of the urine falls, and there is a rise in the amount of 

 chlorids in proportion to the amount of urea. However, the abso- 

 lute quantity of NaCl in the urine diminishes. In health there is 

 approximately double the amount of NaCl in the urine as in the 



