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W. On Larixinic Acid, a crystallizable volatile principle found in the Baric of the 
Larch Tree (Pinus Larix, Linn.). By Dr. John Stenhouse, F.B.S. 
Eeceived Julj 10, — Eead NoTember 21, 1861. 
The most conTenient way of preparing this somewhat singular substance consists in. 
cutting the bark of the larch into small pieces, and then digesting it in water for twenty- 
four hours at a temperature of about 80° Cent. The solution, which has a deep reddish- 
brouTL colour, is then poured oiff on to a second portion of larch bark and digested as 
before. The concentrated infusion is then cautiously heated in an open porcelain dish, 
at the temperature of about 80° Cent., till it is converted into a syrup. A portion of this 
syrup is then distilled, either in glass or porcelain retorts, or, what is better than either, 
in a silver alembic. Iron retorts cannot be employed for this purpose, as the acetic 
acid which is always produced during distillation, by forming acetate of iron, instantly 
destroys the larixinic acid, by changing it into a deep-purple-coloured liquid. When a 
silver alembic cannot be procured, a very convenient way of distilling the extract of the 
larch is to pour it into a large Florence flask, the neck of wdiich is j)assed obliquely 
through a cork or bung, which is mserted into a glass condenser. When the flask is 
cautiously heated on a sand-bath, the larixinic acid comes over with the first portions of 
the liquid, but becomes more abundant as the distillation proceeds, and usually forms 
large flat crj^stals which condense on the sides and neck of the receiver. The liquid 
which is distilled over, and which contains the greater portion of the larixinic acid, 
should be poured into small flat basins, and cautiously concentrated at about 60° Cent. 
When the greater portion of the water has been dissipated, it is advisable, especially in 
warm w'eather, to complete the operation by spontaneous evaporation; for unless the 
concentration of the aqueous solution of larixinic acid is conducted cautiously, the 
larixinic acid volatilizes along with the vapour of water, and is thereby lost. The 
highly concentrated solution of larixinic acid obtained in the way just described, on 
standing, deposits bro^vnish-yellow crystals, which are impure larixinic acid. This is to 
be pressed between folds of blotting-paper, and again to be crystallized out of a small 
quantity of water. The larixinic acid may be rendered perfectly pure by subliming it 
once or twice. This is easily effected by placing the larixinic acid between two watch- 
glasses, or in any other suitable apparatus, and heating it cautiously on a sand-bath, or 
even on a water-bath, as the larixinic acid sublimes at the very low temperature of 
93° Cent. The larixinic acid is a proximate principle, which exists ready formed in the 
larch. This is easily proved by distilhng even a dilute infusion of the bark, when the 
liquid which passes over will be found to strike a deep purple colour with a persalt of 
