URINE. 165 



The admirable researches of Lecarm 1 show that the urine of 

 the same person, analysed at different times, gives nearly uni- 

 form results. 



The urine of persons of different ages and sexes exhibits 

 deviations both in the relative and absolute proportion of its 

 constituents, while in persons of similar ages and sexes, the 

 variations are very trifling. 



The quantity of urine discharged by different persons, 

 in the course of the twenty-four hours, varies considerably, 

 even although the circumstances under which the obser- 

 vations are made are apparently similar. In 16 individuals of 

 different ages and sex, with different but sufficient food, the 

 quantity varied from 18 to 78 ounces. 



The mean specific gravity of the urine of different persons 

 varies. The highest specific gravity was 1030, the lowest 1016. 

 It was most frequently between 1020 and 1030. The urine 

 of men in the prime of life was more concentrated than that of 

 old men, women, or children. 



The quantity of urea amounts, according to Berzelius and 

 Lehmann, to nearly one half of the solid constituents ; accord- 

 ing to my observations, to a little more than a third. It follows, 

 from the experiments of Lehmann, which have just been stated, 

 that these proportions are dependent on the nature of the food; 

 it is certain, however, that they are also dependent on the 

 powers of assimilation, for we know that some persons thrive 

 upon a very frugal, and barely sufficient diet; while others appear 

 half-starved, although taking an abundance of nutritious food. 



According to Lecanu, the quantity of urea which different 

 individuals, living under different circumstances, secrete during 

 the same period, differs greatly ; it approximates, however, in 

 proportion to the similarity of the circumstances. 



In the course of twelve days there was secreted by 



A man aged 20 years, 334 grammes of urea 



22 334 



38 310 



43 351 



53 364 



A woman aged 28 205 



16 210 



A child aged 8 171 



8 168 



1 Journal de Pharmacie, vol. 35, 1839. 



