Remarks on Formic Acid. 145 



bears exposure to a red heat without suffering decomposition, readily 

 changes into ammonia and formate of potassa, by simply boiling a 

 saturated solution of it in water. 



It is known, moreover, to chemists, that oxalic acid, when sud- 

 denly heated to about 300°, becomes changed into formic acid mix- 

 ed with the oxide and acid of carbon and water. More recently, 

 J. Liebig has examined a remarkable acid, composed of the formic 

 acid and the hyduret of Benzule, (oil of bitter almonds,) to which 

 he has given the name of formo-benzoilic* Indeed, it seems re- 

 markable, considering all circumstances, that formic acid does not 

 more frequently arise from the reaction of organic bodies upon each 

 other, and the more especially as there is some reason to presume, 

 with Liebig, that oxide of carbon, like some compounds of carbon 

 and hydrogen, is capable of acting as a radical. Perhaps the rea- 

 son is, that formic acid contains elements feebly united, and (as has 

 been stated in relation to the metallic oxides) readily seizes upon 

 additional proportions of oxygen, and thus changes into carbonic acid 

 and water. 



The following, founded wholly upon a comparison of combining 



proportions, may be mentioned as some of its most direct relations : 



One atom of f 1 atom of oxalic aeid+1 atom of hydrogen. 



formic acid < 1 atom of sugar -f-1 atom of carbonic acid. 



may result from ( 3 atoms of sugar — 1 atom of light carburet of hydrogen. 



Two atoms of (1 atom of tartaric acid +1 atom of oxygen. 



formic acid, from ( 1 atom of malic (or citric) acid-j-2 atoms of oxygen. 



Also, 1 atom of formate of ammonia from 1 atom of prussic acid-{-3 atoms of water. 



Artificial preparation of formic acid. 



I shall now, however, enter upon what must be regarded as the 

 principal object of this communication ; namely, a statement of the 

 results of my own inquiry, by which I have arrived at the conclusion 

 that Prof. Dobereiner's views are erroneous as to the mode of form- 

 ing this acid, and that the principles involved in its production are 

 analogous to, and perhaps equally deserving of notice as, those that 

 relate to the hydric or sulphuric ether. 



One part of tartaric acid (or sugar) — one and a half of peroxide 

 of manganese — one and a half of sulphuric acid, diluted with about 

 two and a half parts of water, when well mixed and subjected to 

 distillation, will furnish the formic acid according to Dobereiner's 

 process. In order to diminish the inconvenience arising from (he 



* Ann. de Chim. Juin, 1836. 



Vol. X^tXIL— No. 1. 19 



