174 
MISCELLANY. 
ny experiments, the following process has been recognised as free from all 
fault : the lower vessel is a circular and flat casting, of the diameter of 
eight or nine inches, and the sides two inches in height. A vessel of iron 
answers the purpose very well. About one pound or less of coarsely bro- 
ken benzoin is to be strewed regularly over the bottom. Over the open- 
ing of the pot, unsized paper of a loose tissue is to be stretched, and fas- 
tened to the sides by paste; a cap of thick wrapping paper is to be placed 
over the whole, and adapted very accurately to the sides of the vessel, so 
that there may be no opening ; this is then to be strongly tied to the base. 
The most certain mode to obtain a uniform application of heat is to place 
a large metallic plate on a tripod, to pour upon it some sand, and to fix so- 
lidly the subliming apparatus thereon; a slow charcoal fire is to be ap- 
plied beneath the plate and kept up for three or four hours, keeping in 
mind that the beauty of the product depends on the regularity of the heat, 
and the slowness of the operation. The plate, placed under the apparatus, 
serves not only to spread the heat, but prevents the ascending current 
from the fire from striking the paper cap. When the operation is terminat- 
ed, the apparatus is to be allowed to cool completely, to be then inverted, 
and the cord detached ; extremely beautiful flowers of benzoin will then 
be found in the cap. A cap of the size and form of an ordinary hat for the 
human head, is preferable to a cone of paper. The essential advantages 
of this method consist in the unsized paper stretched over the vessel, and 
through which the vapors of benzoic acid are compelled to pass. I am 
convinced that it is not necessary to perforate the paper with holes, but 
that the loose tissue suffices for the transmission of the vapors. The flow- 
ers of benzoin deposit, almost completely, their fetid coloring oil during 
their passage. They exhibit a brilliant white appearance, and exhale a 
strong and agreeable odor of benzoin, and the paper is strongly colored by 
the empyreumatic oil. The paper likewise prevents the sublimed flowers 
from falling back into the cake of benzoin, without which there would 
be a constant re-sublimation of the flowers, and, finally, a decomposition ; 
the paper finally prevents the condensed benzoin from being affected by 
the radiant heat from the bottom of the vessel ; so that the condensation 
takes place with greater facility, and, for this reason also, there should 
be no opening in the paper cap. The French pharmacopoeia says the fire 
should be regulated by the disengagement of the vapors; this care is here 
superfluous; a slightly elevated temperature does no harm; because the 
paper cap is always cooled on its exterior, and constantly protected against 
the heat from the bottom of the vessel. The product of sublimed flowers 
is always less than by Scheele's method; there is commonly obtained 
4 p. 100 precisely, as the French Pharmacopoeia points out. A. G. V. 
Journ. de Pharm. 
On the presence and extraction of Carbonate of Soda in Hungary. By A. 
Werner. (Journ, per Practic Chem. ) — The localities most abounding in 
