WATER. 31 



of indefinite chemical composition, and non-crystallizdble, 

 and we have no reason to be surprised, as physiologists, to 

 find it entering into their composition in indefinite propor- 

 tions, assuming the form and consistence of the organic svh- 

 stance. Our definition of a proximate principle is : "a sub- 

 stance extracted from the body, which cannot be further 

 subdivided without chemical decomposition." The union 

 of water with the organic principles is chemical ; and though 

 feeble, is not more so than the chemical union of elements 

 in some compounds found in the inorganic world. The bi- 

 carbonates, for example, are formed by a union of two equiv- 

 alents of carbonic acid with one of the base ; but the second 

 atom of carbonic acid is in so feeble a condition of union, that 

 it is set free when the compound is placed under the receiver 

 of an air-pump. It might be objected that water is combined 

 with organic substances in an indefinite quantity, while the 

 carbonic acid is present in definite proportion ; but it must be 

 remembered that indefinite proportions of all the constituents 

 are characteristic of organic substances ; and that the quantity 

 of water existing, within certain limits, in indefinite propor- 

 tions, only obeys the law which regulates the components 

 which are universally recognized as existing in a state of 

 chemical union. The only difference between water and the 

 other constituents of an organic compound, is that the former 

 is extracted with facility ; as one atom of carbonic acid is 

 extracted from the bicarbonates more easily than the other. 

 Studying the organism as physiologists, we must consider 

 water as an integral constituent of the tissues, and not as 

 merely absorbed by them. 



All the organized structures contain a certain proportion of 

 water, and this is necessary to the performance of all or any of 

 their functions. If a normal muscle be considered as a con- 

 tracting organ, and a nerve as a conducting organ, or albu- 

 men as a nutritious element, we must consider, as one of their 

 constituents, water. It is necessary to the proper form, consist- 

 ence, and function of these and all organized structures. In 

 analysis of organic matters, when water is lost or driven off 



