BULLETIN OF THE BUSSEY INSTITUTION. ban 
hydrazone could be detected at the end of this time it was con- 
sidered to be absent. 
Nine samples of inner bark were treated in the manner just 
described. The results obtained appear in the following table. 
(The word ‘‘ yes” indicates that mannose-hydrazone was de- 
tected. The word ‘‘no” indicates that mannose-hydrazone was 
not detected. ) 
Unevaporated 
Liquid Evaporated Liquid 
o H H o H ra ra 
Kind of Material g a 2 8 = = = 
ie ; @o+B +2 @ +6 +6 +E 
EAccote are Cmts ele | ae 
S OS OO 3) Oven) Sree 
TS ao AN re mao WAN WO 
Inner bark of Fir, cut July5and6,1905 No No No Yes No No No 
Inner bark of Spruce, cut July 7,19095 No No No No No No No 
Inner bark of Pine, cut July 7, 1905 . No No No’ Yes No No No 
‘Inner bark of Fir, cut July 31, 1905 . No No No Yes Yes No No 
Inner bark of Spruce, cut Aug. 7,1905 No No No Yes Tr. No No 
Inner bark of Larch, cut Aug.9, 1905. No No No Yes No No No 
Inner bark of Pine, cut Aug. 12,1905. No No No Yes Yes No No 
Inner bark of Poplar, American aspen, 
Cunaugl0,1905. . .. . No No No No No No No 
Inner bark of Gray Birch, cut ae The 
erent... . . . No No No No No No No 
On comparing these results obtained with barks with those 
previously obtained in this laboratory from woods proper,* it will 
be seen that the barks apparently contain decidedly smaller quan- 
tities of mannan than is contained in the actual woods. Roughly 
speaking, it may be said that at the time of year when mannan is 
present in largest proportion in the wood, there is, according to 
our method of estimation, only about one fourth as much of it in 
the bark; and the question naturally arises if mannan is really 
the source of nourishment in bark bread, why did not the Scandi- 
navians grind wood to a powder in the manner described as well 
as, or rather than, the bark? 
It is noteworthy that while it had been found previously that 
the quantity of mannan in pine wood is apparently largest in 
* Bulletin of the Bussey Institution, 1903, 3. 50. 
