THE KIDNEYS SECRETION OF URINE. 



503 



upon the whole being 519 grains. The proportion to each 1 Ib. of body- 

 weight was, on the whole average, 2.76 grains. But in experiments in prison, 

 either with or without hard labor, the proportion varied from 3.72 to 5.82 

 grains to each 1 Ib. of body-weight; so that he is of opinion that the relative 

 proportion is of no scientific value. There was increase with diminished 

 temperature and with increased atmospheric pressure, and hence variations 

 in the relations of these two agencies varied the results. The increase in the 

 elimination of urea with cold was often deferred until the following day. 

 The period of elimination is not that of production, and whatever increases 

 elimination of urine increases that of urea also. 



Period of the Day. The greatest hourly elimination of urea, in Dr. Smith's 

 experiments, occurred after the breakfast and tea-meals ; whilst it was least 

 during the hours of the night and early morning. Ranke found that it 

 steadily diminished from the morning to the evening. 



Sex. According to Dr. Parkes, the quantity of urea excreted every 24 

 hours, for 1 Ib. of body-weight, is, for men, about 3 grains ; for women, about 

 3 grains. During menstruation, according to Beigel, the excretion of urea 

 diminishes, but subsequently it is increased. 



Food. Variations in the quantity and quality of the food occasion great 

 differences in the proportion of the urea. The following table gives the 

 results in grains of some of the best observers : 



1 Grundzuge der Physiologie, 1872, p. 509. 



2 Lehmann. Phys. Chem. (Cav. Soc. ed.), vol. ii, pp. 450-452. 



3 HMiirrhtnn Dnhlin Oiinrf .Tnurn 1 S.iQ * Hill 



3 Haughton, Dublin Quart. Journ., 1859. 

 5 Vierordt, Phys., 1860. 



Dub. Med. Press. 1859. 



