142 Remarks on Formie Acid. 
will here notice an instance, founded upon my own observation, of a 
very striking nature. Being lately very much struck with the odor 
peculiar to the red oak, I applied my lips closely to the transverse 
section of some fresh cut logs, and, to my astonishment, sucked up 
with ease a pure and grateful vinegar, sharp to the taste, and so like 
the best specimens of the acetic acid that distillation could not have 
improved its qualities. The tree was full grown and sound, and felled 
in the’ month of February, about the 6th, and the wood examined 
as soon as cut. The acetic acid existed most abundantly in the red 
portion next to the heart. 
In some of the arts, where pure acetic acid of medium strength 
is required, (as in making white lead,) it appears to me that the for- 
mic acid might be substituted; for, independently of the fact that 
the latter may be procured pure and concentrated by a single dis- 
poe rom the same bodies which, indirectly, and only by an 
eNSIVE rotten furnish the acetic acid,—their neutralizing powers, 
are widely different, and the advantage is greatly in favor of the 
formic aci e combining proportions being as follows: acetic 
acid 50, sora acid 37, it follows that the difference of weight, 
which amounts to nearly one fourth of the whole acetic acid, would 
be always available were the formic acid employed for the purposes 
of saturation. 
is acid, however, can never be brought to the same degree of 
concentration, because, its elements being in such a ratio as to rep- 
resent, exactly, 2 atoms oxide of carbon+1 atom water, it readily 
suffers decomposition when exposed to the influence of sulphuric 
acid strong enough to remove its constituent water. This, of course, 
always happens when a formate is decomposed by the commercial 
sulphuric acid, and nothing can be more characteristic of the pres- 
ence of formic acid than the brisk effervescence, owing to the escape 
of pure oxide of carbon, whenever the dry formates are heated with 
oil of vitriol. There is no odor of formic acid. The acetates, on 
the contrary, as is well known, furnish the strongest and purest acid 
when submitted to the same treatment. But although this may be 
regarded as a defect for some purposes, the formic acid, obtained 
by decomposing its salts, need never contain more than 20 per cent. 
of water 
To the chemist and pharmaceutist, the formic acid is highly inter- 
esting in consequence of its surprising reducing power; being, in 
this respect, superior even to hydrogen. Like the lampic acid, it 
often promptly revives the noble metals when ine solutions of the 
