Remarlcs on Formic Acid. 141 



It is sufficiently obvious, however, that the product must have 

 been both vi^eak and impure. With the formic acid, thus obtained, 

 exists the raahc acid ; and to separate the latter, as well as to give 

 the necessary concentration, the acids were neutralized by carbonate 

 of potassa, (without excess) — the malic acid then precipitated by 

 acetate of lead, (added only as long as precipitation took place,) and 

 the solution of the formate, thus left, when sufficiently concentrated, 

 decomposed by means of sulphuric acid. Subsequently, distillation 

 was necessary in order to obtain the formic acid itself; yet, even 

 after this, one impurity being substituted for another, (the acetic for 

 the malic acid,) it would become necessary to have recourse to the 

 additional operations of combining the acids with the oxide of lead, 

 and then separating their salts by well managed crystallization, be- 

 fore we could obtain the formic acid free from the acetic. 



It is manifest that an acid, with so very limited a source and so 

 many delays accompanying its preparation, was but ill calculated to 

 excite much general interest. Even after Dobereiner had pointed 

 out the mode by which it could be obtained artificially, and Wohler, 

 Liebig and others, had very much extended the list of substances 

 capable of yielding it by this process, there was found to exist much 

 practical inconvenience, and the formic acid still continues to be 

 known to many chemists, only by description. The last specimen 

 which I purchased cost 50 cents per ounce, although its intrinsic 

 value should not exceed 6J cents, when proper and obvious precau- 

 tions are taken in its formation. 



To the taste this acid is very nearly as grateful as the best vinegar, 

 and, at the same time, so very similar, that one might be substituted 

 for the other by housekeepers. Most persons would certainly con- 

 found them, for even the distinguished chemists, Fourcroy and Vau- 

 quelin, not only deliberately published their conviction of the iden- 

 tity, after an experimental inquiry which had this express object in 

 view, but again asserted the same opinion when their first statement 

 was opposed by the experiments of Suerson, who contended that 

 the formic was a distinct and peculiar acid. The acetic and formic 

 acids have an origin very similar, both coming from the same class 

 of bodies, viz. sugar, starch, gum, wood, &;c. By a species of 

 destructive distillation peculiar to each, both may be got from 

 these substances directly ; but the acetic acid does not appear 

 to yield any notable quantity of the formic, by any operations yet 

 known. In addition to the evidence which H. Braconnot has given, 

 that the former one is frequently generated by living vegetables, I 



