QUANTITY AND COMPOSITION OF THE URINE. 731 



dilated as 1500 cc. for healthy adult men and 1200 cc. for women. The 

 minimum elimination occurs during the early morning between 2 and 4 

 o'clock; the maximum, in the first hours after waking and from 1-2 

 hours after a meal. 



The quantity of solids excreted per day is nearly constant, even though 

 the quantity of urine may vary, and it is quite constant when the manner 

 of living is regular. Therefore the percentage of solids in the urine is 

 naturally in inverse proportion to the quantity of urine. The average 

 amount of solids per twenty-four hours is calculated as 60 grams. The 

 quantity may be calculated with approximate accuracy from the specific 

 gravity if the second and third decimals of this factor be multiplied by 

 HASER'S coefficient, 2.33. The product gives the amount of solids in 

 1000 cc. of urine, and if the quantity of urine eliminated in twenty-four 

 hours be measured, the quantity of solids in twenty-four hours may be 

 easily calculated. For example, 1050 cc. of urine of a specific gravity 

 1.021 was eliminated in twenty-four hours; therefore the quantity of 



solids excreted was 21X2.33 = 48.9 and ^4^ ^5-51.35 grams. LONG l 



1000 



has made a new determination of the coefficient for a specific gravity 

 taken at 25 C. and finds that it is equal to 2.6, which almost corresponds 

 to HASER'S coefficient at 15 C. 



Those bodies which, under physiological conditions, affect the density 

 of the urine are common salt and urea. The specific gravity of the first 

 is 2.15 and the last only 1.32, so it is easy to understand, when the relative 

 proportion of these two bodies essentially deviates from the normal, 

 why the above calculation from the specific gravity is not exact. The 

 same is true when a urine poor in normal constituents contains large 

 amounts of foreign bodies, such as albumin or sugar. 



As above stated, the percentage of solids in the urine generally decreases 

 with a greater elimination, and a very considerable excretion of urine 

 (polyuria) has therefore, as a rule, a lower specific gravity. An important 

 exception to this rule is observed in urine containing sugar (diabetes melli- 

 tus), in which there is a copious excretion with a very high specific gravity 

 due to the sugar. In cases where very little urine is excreted (oliyuria), 

 e.g., during profuse perspiration, in diarrhoea, and in fevers, the specific 

 gravity of the urine is as a rule very high; the percentage of solids is also 

 high and the urine has a dark color. Sometimes, as for example in certain 

 cases of albuminuria, the urine may have a low specific gravity notwith- 

 standing the oliguria, and be poor in solids and light in color. 



In certain cases it is interesting to know the relation between the 

 carbon and the nitrogen, or the quotient C/N. This factor may vary 

 between 0.7 and 1 ; as a rule, it amounts on an average to O.S7, but changes 



1 Journ. Amer. Chem. Soc., 25. 



