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Aet. II . — On the Antiseptic Power of the Pyrolignous Acid. 
By Mr William Ramsay. Communicated by the Author. 
About twelve months ago, it was notified in the newspapers, 
that the acid formed by the destructive distillation of wood, com- 
monly called the Pyrolignous Acid, has the property of preserv- 
ing animal substances from putrefaction. 
Since this fact was announced, I have tried a variety of expe- 
riments on this subject, not only as a matter of curiosity, but 
also with the view of rendering the acid serviceable in domestic 
economy, and in particular for the preservation of animal sub- 
stances used as provisions in the victualling of ships. 
The pyrolignous acid, the product of the distillation of wood, 
is now well known in Britain as an article of commerce, and in 
its native state is a liquid of a white wine colour, possessing a 
strong acid slightly astringent taste,' combined with an empy- 
reumatic smell. When this acid is allowed to remain in a state 
of rest for eight or ten days, tar of a black colour subsides, and 
the acid is then comparatively transparent. To purify it fur- 
ther, it undergoes the process of distillation, by w^hich it is freed 
from a still greater portion of the tar wdth which it is combined, 
and it is thus rendered still more transparent. But though the 
process of distillation is repeated without end, it will never be 
freed from the volatile oil with which it is combined, 'and which 
is the cause of the empyreuma constantly combined with it. 
From the above sketch of the qualities of this acid, it may 
be perceived that it contains the same properties for the preser- 
vation of animal matters from putrefaction that the smoking 
them by wood does, which is practised at present by the most 
barbarous nations, and which has been handed down from the 
remotest ages of antiquity. 
In the curing of red herrings in this country, the fish, after 
being freed from the gut, are partially salted, and then suspend- 
ed by the eye-holes on rods of wood, in a house constructed for 
the purpose, on the floor of which fires of wood are lighted, and 
kept burning night and day with a smothered heat, until it is 
ascertained that the herrings are fully cured. If red herritigs 
