108 BULLETIN OF THE BUSSEY INSTITUTION. 
Tests for Mannite in Woods. 
White Pine Wood. — Two attempts were made to find mannite in 100 grm. 
portions of the wood of a white pine tree collected at Hingham, Mass., in 
August, 1903, and one of the trials indicated that small quantities of mannite 
might possibly be present. That is to say in the trial where 100 grm. of the 
wood were percolated, a few crystals resembling those of mannite appeared in 
the filtrate from the copper sulphide, and on treating these crystals with ferrous 
sulphate and hydrogen dioxide and subsequently with phenylhydrazin acetate, 
a small quantity of balls and crystals resembling those of mannose-hydrazone 
were obtained. In the other trial where the wood was percolated with hot 
alcohol of 75% only a negative result was obtained. Though the results 
of the first trial were by no means wholly satisfactory they went to show the 
probability of mannite in the pine wood. Yet another trial made with pine 
wood collected in the spring, viz., on April 9, 1908, and percolated with hot 
water gave no indications of mannite. 
Gray Birch Wood.— No mannite was detected in a 100 grm. sample of 
the wood of a gray birch tree (Betula popultfolia) collected in October, 1895. 
Inlac Wood. — In view of the fact that several chemists have reported the 
presence of mannite in young twigs and leaves of the common lilac (Syringa 
vulgaris).samples of these materials were subjected repeatedly to the method - 
of testing which has been described above. Thus 60 grm. of dried leaves of 
the purple lilac plucked on May 7, 1903, were percolated and examined in 
January, 1904, but no mannite was detected. 
100 grm. of lilac wood (free from bark) collected on May 7, 1903, and 
examined in February, 1904, gave no reactions for mannite. 
Twigs ;°; to 4 inch in diameter cut from a. purple lilac bush on April 11, 
1904, were freed from bark and were percolated and treated in the usual way. 
No mannite was detected. 
Fresh young half-formed leaves of a purple lilac collected on May 10, 1904, 
gave finally some not particularly well formed crystals which may have been 
mannose-hydrazone though the quantity obtained was not large and the 
result was not really satisfactory. 
Fresh young lilac shoots that had begun to be formed from buds on the 
twigs were collected on April 11, and allowed to dry. The powdered material 
was percolated and treated as usual. Some crystals that separated on evapora- 
ting the filtrate from the copper sulphide appeared to be dulcite rather than 
mannite and suggested the thought that previous observers may perhaps really 
have had to do with dulcite rather than mannite in their experiments on the 
lilac. None the less, in the final test with phenylhydrazin acetate, a few 
crystals were obtained which may possibly have been mannose-hydrazone, 
though the evidence was not conclusive. 
