302 THE URINE. 



be stated that whenever such substances find their way into the 

 general circulation their elimination at once follows. Formerly 

 it was taught that peptones could thus appear, and for many years 

 various types of peptonuria were described. More recent investiga- 

 tions, however, have shown that the substances in question were in 

 reality no peptones in the sense of Kiihne, but albumoses. Some 

 of these are, no doubt, identical with the common digestive albu- 

 moses, and find their way into the blood, when their further trans- 

 formation into native albumins does not occur in the epithelial 

 cells of the digestive tract. Others again are probably formed in 

 the body proper in diseases which are associated with suppurative 

 processes, and in which the formation of albumoses occurs at the 

 expense of the tissue albumins under the influence of various micro- 

 organisms. Under still other conditions, as in the various non- 

 septic fevers, in phosphorus poisoning, etc., the albumosuria may 

 be the expression of a metabolic abnormality per se, and is possibly 

 dependent upon the action of the various tissue ferments. 



Of special interest, further, is the appearance in the urine of the 

 so-called albumin of Bence Jones, which has been repeatedly ob- 

 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. In every urine a more or less well-marked white ring appears 

 in the upper strata of the specimen and separated from the albumin 

 rincr (if present) by a layer of clear urine. This was formerly re- 

 garded as being referable to uric acid, but Morner has shown that it 



