482 



PHYSIOLOGICAL CHEMISTRY 



TABLE I 



No. 



i 



2 



3 

 4 



6 



9 

 10 

 n 



12 

 13 



NaH 2 PO 4 



o.oooi N 

 o.oooi N 

 0.0166 N 

 o.ooio N 

 o.ooio N 



Na 2 HP0 4 



o.iooo N 

 o . 0480 N 



O.OI2O N 



0.0833 N 

 0.0060 N 

 0.0023 N 



Indicator 



9.27 ] 



8.7 \ Phenolphthalein 



8.0 J 1 



7.48 



7.38 



6.90 J 



> Neutral red 



CHsCOOH CH 3 COONa 



TABLE II 



Log 



4.6 

 4-8 

 5-0 

 5-2 

 5-4 

 5-6 

 5.8 

 6.0 

 6.2 



H 



160X10-7 

 iooXio-7 



25X10-7 

 i6Xio-7 



6.3x10-7 



Log 



6.4 

 6.6 

 6.8 

 7-0 

 7.2 

 7-4 

 7.6 

 7.8 

 8.0 



4.0 

 2.5 



1.6 



1.0 



0.63x10-7 

 0.40x10-7 

 0.25x10-7 



O.I6XIO-7 



o.ioXio" 7 



Interpretation. The H ion concentration of the urine is influenced 

 by the same factors as the titratable acidity (see page 480). The 

 normal values lie between 4.80 and 7.50 with a mean value of almost 

 exactly 6.00. For vegetarians the mean value is about 6.64. In 

 cardio-renal disorders the mean is 5.3. In most pathological conditions 

 the hydrogen ion concentration is increased. 



Total Solids 



i. Drying Method. Place 5 c.c. of urine in a weighed shallow dish, acidify 

 very slightly with acetic acid (1-3 drops), and dry it in vacuo in the presence of sul- 

 phuric acid to constant weight. Calculate the percentage of solids in the urine 

 sample and the total. solids for the 24-hour period. 



Interpretation. The average excretion of total solids by a normal adult man is 

 about 70 grams. It is largely dependent upon the protein and salts of the diet. 

 It may be decreased in severe nephritis due to impaired excretion, and greatly in- 

 creased in diabetes with high sugar elimination. 



Practically all the methods the technic of which includes evaporation at an 

 increased temperature, either under atmospheric conditions or in vacuo, are attended 

 with error. 



ShackelPs method 1 which entails the vacuum desiccation of the frozen sample 

 is extremely satisfactory and should be used in all biological work where the great- 

 est accuracy is desired. 



1 Shackell: American Journal of Physiology, 24, 325, 1909 



