BULLETIN OF THE BUSSEY INSTITUTION. 109 
Tests for Mannite in Fruits. 
Dried Figs of commerce bought in Boston, July 7, 1904, were cut into 
small pieces which were ground in a mortar together with clean sharp sand to a 
friable mixture fit to be percolated with hot water. On allowing the percolate 
to stand over night at the ordinary temperature of the air, it solidified to a 
jelly which liquefied however on the addition of a small quantity of water and 
warming the mixture. The solution was now readily filtered and it remained 
limpid on cooling, but to our surprise no precipitate formed on adding some 
of the ammoniacal copper sulphate and none appeared on standing, not even 
when the mixture was left at rest until the next day. In the belief that the 
matter which had previously gelatinized might perhaps act to hold the mannite- 
copper compound in solution, basic acetate of lead was added to a small por- 
tion of the fig liquor (to which some drops of the ammoniacal copper sulphate 
had already been added), and the copious flocculent precipitate of lead oxide 
combined with organic matter was removed by filtration. On adding to the 
clear filtrate a new quantity of the ammoniacal copper sulphate a blue precipi- 
tate fell at once which was decomposed by sulphuretted hydrogen in the usual 
way. On evaporating the filtrate from the copper sulphide fine needle-like 
crystals were obtained which gave mannose-hydrazone balls and some excellent 
crystals of mannose-hydrazone, on being treated with ferrous sulphate, hydro- 
gen dioxide and phenylhydrazin acetate. A similar result was obtained when 
the remainder of the fig liquor was mixed with basic lead acetate and the clear 
filtrate was thereafter treated with the ammoniacal copper sulphate, etc. It 
was evident enough that the figs contained mannite though perhaps in no very 
large proportion. 
To see if any of the mannite-copper compound had been dragged down 
with the precipitate produced by the basic lead acetate, a quantity of this 
heavy precipitate was suspended in water and decomposed with sulphuretted 
hydrogen. After removal of the lead sulphide, the filtrate was evaporated as 
far as possible and the viscous residue was left in a cool place for several 
days. No crystals of mannite appeared and no reaction for this substance 
was obtained on dissolving the residue in water and treating it with ferrous 
sulphate, hydrogen dioxide, and phenylhydrazin acetate. 
Cherries. — Large white cherries, firm and sound, that had grown in the 
vicinity of Boston, were bought on July 14, 1904. After removing the stems 
and stones, the flesh of the fruit was cut into small pieces and rubbed in a 
mortar toa pulp. The juice expressed by the rubbing was filtered and added 
in due course to the percolate obtained by heating some 300 grm. of the pulp 
with hot water. After evaporating the solution it was found to be somewhat 
acid and it was almost but not quite neutralized with sodium carbonate. On 
adding ammoniacal copper sulphate to a part of this solution no precipitate 
fell, not even when the mixture was left to stand over night. Basic lead 
acetate was added to the remainder of the solution, the precipitate that formed 
was removed by filtration and the excess of lead was thrown down by means 
of sulphuretted hydrogen. On adding ammoniacal copper sulphate to the 
