104 BULLETIN OF THE BUSSEY INSTITUTION. 
of percolation, precipitation with ammoniacal copper sulphate, 
and oxidation with hydrogen dioxide. _ Another positive result 
was obtained on examining fresh leaves plucked from the stems of 
bottle grass (Setaria viridis) early in September, 1903. The 
grass had flowered and some seeds had begun to ripen. Neither 
the stems nor the seeds were examined, but only the lower leaves. 
In this case 60 grm. of the fresh leaves cut into small pieces were 
extracted with 250 cc. of boiling aleohol of 75% ; the alcohol was 
driven off and the residue after having been washed with alcohol 
of 95% and with ether was taken up with repeated portions of 
boiling alcohol of 85%. In this way small successive crops of 
crystals of mannite were obtained which when treated with ferrous 
sulphate and hydrogen dioxide and subsequently with phenyl- 
hydrazin acetate gave crystals of mannose hydrazone. 
An equal quantity (60 grm.) of the fresh leaves of the bottle 
grass was allowed to dry slowly during a fortnight on a shelf not 
exposed to the sun’s rays, care being taken to turn the leaves once 
a day. The dry leaves were leached with alcohol as the fresh 
leaves had been leached and mannite was obtained from them 
apparently in somewhat larger quantity than had been got from the 
fresh leaves. Mannose hydrazone crystals also were obtained in 
due course. This method of extracting with alcohol is incon- 
venient because the mannite crystals are contaminated with 
much gummy matter. 
It needs to be said emphatically that the foregoing three positive results, 
viz., the finding of mannite in oat hay, in June grass hay, and in the leaves of 
maturing bottle grass, differ decidedly from the results of the examination of 
various grasses collected at earlier stages of development for the most part, 
while growing in the fields. Thus, no mannite was detected in the samples of 
grasses mentioned in the following list :— 
Fresh leaves of June grass collected on September 26, 1903. 
Leaves of the June grass of September 26, that had been allowed to dry 
slowly in the shade. 
Fresh leaves, each about 4 inches long, of tender young June grass collected 
on May 2, 1904. 
Leaves of the June grass of May 2, that were allowed to dry slowly until 
May 26. 
Fresh leaves and stalks of June grass collected on May 24 when the grass 
was 6 inches high and not yet in flower though buds had formed. 
Leaves and stalks of the June grass of May 24 that were allowed to dry 
slowly until June 15. : 
