286 THE URINE. 



served in association with multiple myelomata of the bones. Of its 

 chemical nature, however, little is known. By some it is regarded 

 as an albumose, but, according to Neumeister, it is not identical 

 with any of the known digestive albumoses. I shall revert to it 

 later. 



In diseases, finally, in which an increased destruction of leuco- 

 cytes is taking place, both histon and nucleohiston have been found. 



Of other albumins which are foreign to the blood, only egg- 

 albumin has been encountered, following the ingestion of excessive 

 amounts of the substance. 



Tests for the Common Albumins of the Blood. THE NITRIC 

 ACID TEST. A small amount of urine is placed in a conical glass 

 and is underlaid with a few cubic centimeters of concentrated nitric 

 acid, when in the presence of serum-albumin and serum-globulin a 

 white, opaque disk of coagulated albumin is formed at the zone of con- 

 tact, which varies in intensity and extent with the amount of albumin 

 present. Immediately below this variously colored rings also are 

 observed, which are in part referable to the decomposition of 

 indoxyl and skatoxyl sulphate, and the oxidation of the liberated 

 indoxyl and skatoxyl to blue and red pigments. In the presence 

 of bile-pigment a green color will then also be noted. If much 

 urea be present at the same time, it may happen that after a few 

 minutes a dense disk of urea nitrate crystals separates out in the 

 lower pigmented layer, but more commonly these are formed 

 throughout the mixture on standing, and gradually settle to the 

 bottom. Should uric acid, further, be present in increased amount, 

 a white disk develops higher up in the urine, and separated from 

 that referable to albumins by a layer of clear urine. This may at 

 times be quite marked, and may extend downward toward the nitric 

 acid so rapidly that it is difficult to say whether it is referable to 

 albumin or a large excess of uric acid. Should this occur, it is best 

 to dilute the urine with an equal volume of water, or, even more 

 strongly, when a portion of the uric acid at least is prevented from 

 separating out or is held in solution altogether. 



As nucleo-albumins, when present beyond traces, can simulate 

 the true albumin reaction, it is well to dilute the urine with water 

 and to examine again when its presence is suspected. If then the 

 reaction is more pronounced than before, the precipitate may, in part 

 at least, be referable to this source. This possibility should be con- 

 sidered if the urine contains an increased number of morphological 

 elements, and if the reaction is slight. Other tests should then also 

 be employed. 



Albumoses, if present beyond traces, also react with nitric acid, 

 but it is to be noted that in such cases the precipitate disappears on 

 heating and reappears on cooling, while the liquid at the same time 

 assumes an intensely yellow color. Should a mixed albuminuria 

 exist i. e., should albumoses and albumin be present simultane- 

 ously the clearing of the urine is only partial. 



