PHYSIOLOGICAL CHEMISTRY. 



in tropical countries, but is not entirely unknown in more temperate 

 climates. Albumin is a constant constituent of the urine in chyluria. 

 Upon shaking a chylous urine with ether the fat is dissolved by the 

 ether and the urine becomes clearer or entirely clear. 



H^MATOPORPHYRIN. 



Urine containing this body is occasionally met with in various 

 diseases but more frequently after the use of quinine, tetronal, tri- 

 onal and especially sulphonal. Such urines ordinarily possess a 

 reddish tint, the depth of color varying greatly under different con- 

 ditions. 



EXPERIMENTS. 



1. Spectroscopic Examination. To 100 c.c. of urine add about 

 20 c.c. of a 10 per cent solution of potassium hydroxide or ammon- 

 ium hydroxide. The precipitate which forms consists principally of 

 earthy phosphates to which the haematoporphyrin adheres and is 

 carried down. Filter off the precipitate, wash it and transfer to 

 a flask and warm with alcohol acidified with hydrochloric acid. 

 By this process the hsematoporphyrin is dissolved and on filtering 

 will be found in the filtrate and may be identified by means of the 

 spectroscope (see page 207, and Absorption Spectra, Plate II). 



2. Acetic Acid Test. To 100 c.c. of urine add 5 c.c. of glacial 

 acetic acid and allow the mixture to stand 48 hours. Haematopor- 

 phyrin deposits in the form of a precipitate. 



LACTOSE. 



Lactose is rarely found in the urine except as it is excreted by 

 women during pregnancy, during the nursing period or soon after 

 weaning. It is rather difficult to show the presence of lactose in 

 the urine in a satisfactory manner, since the formation of the 

 characteristic lactosazone is not attended with any great measure 

 of success under these conditions. It is, however, comparatively 

 easy to show that it is not dextrose, for, while it responds to re- 

 duction tests, it does not ferment with pure yeast and does not 

 give a dextrosazone. An absolutely conclusive test, of course, is 

 the isolation of the lactose in crystalline form (Fig. 75, p. 220) 

 from the urine. 



On oxidation with nitric acid lactose and galactose yield mucic 



