438 PHYSIOLOGICAL CHEMISTRY 



portion, place the thumb tightly over the opening in the apparatus and invert the 

 saccharometer. Remembering that KOH has the power to absorb CO a how 

 do you explain the result? 1 . 



Mathews 2 suggests an easy method for differentiation and estimation of 

 lactose in presence of glucose, based on reduction before and after fermentation 

 with yeast. 



4. Polariscopic Examination. For directions as to the use of the polariscope 

 see Chapter II. 



PROTEINS 



Normal urine contains a trace of protein material, but the amount 

 present is so slight as to escape detection by any of the simple tests in 

 general use for the detection of protein urinary constituents. The 

 following are the more important forms of protein material which have 

 been detected in the urine under pathological conditions: 



(1) Serum albumin. 



(2) Serum globulin. 



Deutero-proteose. 



(3) Proteoses 



Hetero-proteose. 



"Bence- Jones' protein." 



(4) Peptone. 



(5) Nucleoprotein. 



(6) Fibrin. 



(7) Oxyhemoglobin. 



ALBUMIN 



Normal urine contains a trace of albumin which is too slight to be 

 detected by the usual procedures. 



Albuminuria is a condition in which serum albumin or serum globulin 

 appears in the urine. There are two distinct forms of albuminuria, i.e., 

 renal albuminuria and accidental albuminuria. Sometimes the terms 

 "true" albuminuria and "false" albuminuria are substituted for those 

 just given. In the renal type the albumin is excreted by the kidneys. 

 This is the more serious form of the malady and at the same time is more 

 frequently encountered than the accidental type. Among the causes of 

 renal albuminuria are altered blood pressure in the kidneys, altered 

 kidney structure, or changes in the composition of the blood entering 

 the kidneys,, thus allowing the albumin to diffuse more readily. In the 

 accidental form of albuminuria the albumin is not excreted by the 



1 The findings of Neuberg and associates indicate that the liberation of carbon dioxide 

 by yeast is not necessarily a criterion of the presence of sugar. The presence of an enzyme 

 called carboxylase has been demonstrated in yeast which has the power of splitting off COi 

 from the carboxyl group of amino- and other aliphatic acids. 



2 Mathews: Jour. Am. Med. dss'n, 75, 1568, 1920. 



