CHLORIDE OF SODIUM. 243 



an interchange of constituents with the carbonate and phosphate 

 of potash, and, on the other hand, that nature has assigned very 

 different parts in the animal organism to the alkalies, which are 

 otherwise so similar when considered from a chemical point of 

 view. Similar conclusions may be deduced from the experiments 

 made at Giessen on different terrestrial animals, which showed 

 that the bile, notwithstanding a food rich in potash, contains a 

 large amount of soda, which is combined with the biliary acids. 

 The great persistence of this distribution of these two alkalies in the 

 various animal juices precludes the idea that we have here to deal 

 with a phenomenon which is merely incidental. As we have already 

 observed, it still remains for us to discover the properties to 

 which the soda owes its place in the blood-serum and in the bile, 

 and to explain the purposes which are effected by the accumu- 

 lation of potash in the juice of the muscular and of all the con- 

 tractile tissues, as well as in the blood-cells, the plastic exudations, 

 the yolk, &c. 



The constant presence in the blood of a tolerably uniform 

 amount of chloride of sodium has led Liebig to the ingenious idea 

 that this very constancy exerts an essential influence on the 

 absorbing power of the blood. This assertion of Liebig's that 

 the constant amount of chloride of sodium present in the blood is 

 an essential agent in the organic process of absorption, must be 

 universally admitted as correct by all who have witnessed even a 

 single endosmotic experiment, and who are moreover well aware 

 that the substances which are actually dissolved in the intestinal 

 canal generally present a far less dense fluid than the blood, and 

 that the kidneys possess a property, which has not yet been ex- 

 plained, of immediately carrying off any excess of water that has 

 entered the blood. If we further add the peculiar relation of 

 acids and alkalies first noticed by Jolly and Graham in diffusion 

 and endosmosis (see p. 218), we shall be disposed, with Liebig, to 

 admit that in the animal body are united all the conditions for 

 rendering the circulating system, by means of the blood, a most 

 perfect suction-pump, which performs its duties without stop-cocks 

 or valves, without mechanical pressure, nay, without regular canals 

 or passages for the transmission of the fluids. 



In conclusion, we must again refer to the remarks which have 

 been previously made (vol. i, p.434, and vol. iii, p. 136) in reference 

 to the influence of chloride of sodium upon the development of 

 cells in secretions and exudations. Amongst the latter we found 

 that the most plastic were those which contained soluble phos- 



R2 



