166 THE SECRETIONS: 



The quantity of urea is greatest in men in the prime of life ; 

 it is greater in women than in old men, or children. It 

 amounts in 



Mean. Maximum. Minimum. 



Men . . 432 509 357 grains 



Women . . 294 436 153 



Old men . . 125 189 60 



Children aged 8 .207 253 161 



4 .69 82 57 



The quantity of urea excreted by the same individual in twenty- 

 four hours, is always nearly the same; and if instead of twenty 

 four hours, we compare it for a longer period, the deviation 

 will be still less marked. 



The quantity of uric acid excreted in twenty-four hours by 

 persons of different age and sex, and living under different cir- 

 cumstances, is as variable as the quantity of urea. It fluctuated 

 between 1-38, and 24-25 grains. A comparison of the quan- 

 tities of uric acid excreted during a longer period by persons 

 of the same age, sex, &c. will show that they nearly coincide. 



In twelve days there were excreted by 



A man aged 20 years, 11 '945 grammes of uric acid 

 22 * 11-967 



38 13-434 



In eight days there were excreted by 



A girl aged 19 years, 3-778 grammes of uric acid 

 A woman aged 43 3-619 



The quantity of uric acid excreted by the same person during 

 the same period (a period of some days for instance) is always 

 nearly constant. This observation is confirmed by the analyses 

 of Lehmann, and myself. 



The amount of fixed salts, (earthy phosphates, chloride of 

 sodium, alkaline sulphates and phosphates,) excreted in twenty- 

 four hours, varies considerably with age and sex. It fluctuated 

 (in Lecanu's analyses) between 378 and 75 grains. There was 

 apparently no uniformity in the amount of these salts in the 

 urine of the same person during different equal periods. For 

 instance, in a man aged 20, the amount of fixed salts in the urine 

 of twenty-four hours, was determined four times. It varied 

 from 348 to 224 grains. 



In men, in the prime of life, the amount of fixed salts is 

 higher than in aged persons, children, or women. 



