212 EXCRETION. 



proportion of chloride of sodium in the blood seems to be 

 tolerably constant ; and any excess that may be introduced 

 is thrown off chiefly by the kidneys. It has been shown con- 

 clusively that deprivation of common salt in the food after 

 a time is followed by serious disturbances in the general pro- 

 cess of nutrition ; and it is an acknowledged fact that this 

 proximate principle is a constituent of every tissue of the 

 body, except the enamel of the teeth. As the chlorides are 

 deposited with the organic matter in all the acts of nutrition, 

 they are found to be eliminated constantly with the products 

 of disassimilation of the nitrogenized parts, and their absence 

 from the food does not completely arrest their discharge in the 

 urine. According to Robin, by suppressing salt in the food, 

 its daily excretion may be reduced to from thirty to forty-five 

 grains, the normal quantity being from one hundred and 

 fifty to one hundred and sixty grains. This quantity is less 

 than the amount contained in the ingesta, and under these 

 circumstances there is a gradual diminution in the nutritive 

 activity. " This fact demonstrates the necessity of adding 

 chloride of sodium to the food." J It is an interesting patho- 

 logical fact, that in all acute febrile disorders, the proportion 

 of chlorine in the urine rapidly diminishes, and is frequently 

 reduced to one hundredth of the normal amount. 3 The 

 quantity rapidly increases to the normal standard during 

 convalescence. Most of the chlorides of the urine are in 

 simple watery solution; but a certain proportion of the 

 chloride of sodium exists in combination with urea. 



The daily elimination of chloride of sodium is about one 

 hundred and fifty-four grains (Robin). The great variations 

 in its proportion in the urine under different conditions of 

 alimentation, etc., will explain the differences in the esti- 

 mates given by various authorities. 



the Urine, New Sydenham Society, London, 1863, p. 396. ROBIN, Lemons sur Ifs 

 humeurs, Paris, 1867, p. 662. 



1 ROBIN, op. cit., p. 663. 



2 NEUBAUER AND VOGEL, op. cit., p. 397. 



