46 
ON THE MANUFACTURE OF WOOD-NAPHTHA. 
the fruit here described may not belong to two species instead of 
one ; but this is far from probable. — Proceedings of the Royal Society 
of Edinbugh. 
[Although several months have elapsed since the above paper 
was read, its value is increased by the following extract of a letter 
from the author, which accompanied a copy of the paper : — ] 
" I am now able to inform you further, that the plant described 
in my paper, 4 On the Gamboge Tree of Siam,' is dioecious ; that 
additional specimens confirm all therein stated, and that the con- 
crete juice of which a small portion has been sent to me, possesses 
all the sensible qualities of the finest Siam pipe-gamboge of com- 
merce. I have no longer any doubt that we have hit on the true 
tree at last. There may be a shade of question raised whether Dr. 
Almeida's trees, of which he has three about twelve feet in height, 
may not belong to more than one species, and, therefore, which of 
them may be the true gamboge bearer. But I have myself scarcely 
any doubt that there is only one species. With a little more infor- 
mation, which I expect to have in six or eight months, I shall be 
in a condition to give a complete account of the matter. But mean- 
while it may interest you and your friends to know what has been 
already done. — Pharmaceutical Journal, November 1, 1850. 
ON THE MANUFACTURE OF PYROXYLIC SPIRIT, OR WOOD- 
NAPHTHA, ACETATE OF LIME, AND ACETONE, OR PYROACETIC 
SPIRIT, 
By Jacob Bell. 
Editor of the [London] Pharmaceutical Journal. 
Separation of the Liquid Products of Distillation from each 
other. — The condensed liquid products before described, [resulting 
from the distillation of wood in iron cylinders] form by subsidence 
in the tank or receptacle two layers, the lower, composed of tarry 
and oily matters, and the upper containing the acid and spirituous 
parts of the products. If two tanks be provided, the one at a 
lower level then the other, the acid and spirituous liquor passes by 
means of an overflow-pipe into the lower tank, and thus become 
separated from the tar ; and if the acid liquor in passing from one 
tank to the other be made to traverse a suitable filter, a large por- 
