TREATMENT. 12^ 



when saturated with salt, the compound to be administered 

 largely diluted with water. 



It may be also urged that this acid represents chemically 

 the fruit acids — at least the one most common in this climate 

 and country — Malic Acid, Liebig regards all the organic 

 acids as having an analogous constitution, and deems it 



" the most natural supposition that they contain in each case a com- 

 pound radical, of which Hydrogen is an element ; in such a manner 

 therefore that the conversion of Carbonic Acid into an organic acid 

 has been effected by the replacement of a part or of the whole of 

 the oxygen of the radical, by hydrogen." 



In this way, and on this supposition, he makes the formulae 

 of Acetic and Malic Acids the same, and adds : 



"It is easy to see that the formulae of Acetic and Malic Acids cor- 

 respond to that of Oxalic Acid (only being doubled), and that Tar- 

 taric Acid is Carbonic Acid, in which half the oxygen of the radical 

 has been replaced by hydrogen, while one-fourth of the oxygen 

 external to the radical has been separated or expelled without 

 replacement."* 



It is not to be inferred, however, that the chemical theory 

 of equivalents as thus expressed, is to serve as a foundation 

 for equivalent medical action ; or that any such experience 

 as is found in the laboratory would be repeated in the 

 stomach of either man or beast. But the manipulations and 

 conclusions of the chemist may serve as our sufficient autho- 

 rity for introducing these acids under the general classification 

 and at the point we proposed at first on grounds of con- 

 venience. 



And here it may meet a scientific requirement, to bring 

 to notice other primordial elements of blood-food. In 

 such way this branch of our inquiry may take to itself a more 

 perfect unity. We have cited common salt as the representa- 



* Animal Chemiatry, p. 68, Amer'n (3d London) edition. The formulae are as follows ; 



Tartaric Acid, €4^2 I 4. O3 = 4 r 4. 3 o. 



