MISCELLANY. 
237 
Analysis of Galls.' By Guibourt. — Galls contain, according to the au- 
thor, the following constituents which pre-exist in them : — 
Water, 11.5; woody fibre, 10*5; tannine, 65 : gallic acid, 2. Ellagic 
acid and luteo-gallic acid, 2. Brown extractive substance, 2.5. Gum, 
2.5. Starch, 2. Chlorophylle and volatile oil, 0.7 ; sugar, 1.3 ; albu- 
men and salts. 
The author assigns the name of luteo-gallic acid to the yellow colour- 
ing principle of the galls. It may be separated from ellagic acid by dis- 
solving the two in potash and exposing the solution to the atmosphere ; 
ellagate of potash is deposited in proportion as carbonic acid is absorbed 
from the air, while the luteo-gallate of potash remains in solution. — 
Ibid, from Ann. der Chem. und Pharm. 
Decomposition of the Golden Sulphur et of Antimony by Light. — M. 
Ingenohl has observed, that carefully prepared golden sulphuret, which 
has been quickly dried in a shady place, keeps for a long time in dark 
vessels undecomposed, but becomes paler when exposed to light, and 
then yields on analysis an amount of oxide of antimony and sulphuric 
acid. Wackenroder confirms this observation, and likewise that of Ot- 
to, that the precipitated golden sulphuret always contains an amount of 
oxide when dried by exposure to the air. The preparation precipitated 
from the sulphuret of antimony and sodium does not undergo so remark- 
able a decomposition by light. — Ibid, from Ibid. 
On the occurrence of Mannite in the Laminaria soccharina, and other 
sea weeds. By John Stenhouse, Ph.D. — After reviewing the experi- 
ments and published reports of various authors, Dr. Stenhouse proceeds 
to detail the examination of a great variety of sea-weeds; out of eight 
different species examined, mannite was separated, and in the case of 
the Laminaria saccharina amounting to 12*15 per cent. The method of 
separation consisted in digesting the dried extract by hot water, with 
boiling alcohol, and allowing the mannite to crystallize out by cooling; 
as thus obtained its composition was C 6 H 7 O 8 . Mannite may be dis- 
tinguished from cane-sugar by its not being discoloured from the action of 
strong sulphuric acid and a gentle heat; and from grape-sugar by boil- 
ing with strong solution of caustic potash or soda, the mannite dissolv- 
ing without change of colour. When heated with solution of potash 
and sulphate of copper, it does not precipitate the red oxide of copper, as 
is the case with grape-sugar. 
Dr. Stenhouse could not detect mannite in the Couch-grass, as stated 
by Prof. Pfaff, but obtained crystals of binoxalate of potash, which ap- 
pear to have been mistaken for the former substance. — Chem. Gaz. 
