BULLETIN OF THE BUSSEY INSTITUTION. AZ 
No. 3.— Notes on the Occurrence of Mannan in the Wood 
of some kinds of Trees, and in various Roots and Fruits. 
By F. H. Srorer, Professor of Agricultural Chemistry. 
THE presence of mannan in the wood of certain coniferous 
trees has been detected by several chemists, and the generality of 
its occurrence in such trees has been confirmed and illustrated by 
numerous experiments made in the Bussey laboratory. 
As has been explained in a previous article,* some evidence 
was met with in the course of those researches which pointed 
towards the conclusion that mannan may perhaps be more abun- 
dant in pine trees at certain seasons of the year than at others, 
and it was for the purpose of testing this supposition that a series 
of new experiments has been carried out on a somewhat different 
plan from the earlier tests. 
Once a month during eleven months of a whole year a limb 
from 1.5 to 2 inches in diameter was cut from a young and thrifty 
white pine tree (P. strobus)} and reduced to splinters which were 
dried and ground to powder. A quantity of the powder equal to 
about twenty grams of matter reckoned as dry at 100° C. was boiled 
in a flask, with reflux condenser, during three hours with ten times 
as many cc. of hydrochloric acid of 5 per cent. as there had been 
taken grams of the air-dried material. For example, 220 cc. of 
the acid would be used upon 22 grams of the powder. At the 
end of the hydrolysis the contents of the flask were left to stand 
during several hours before filtering, the undissolved matter was 
washed with 20 cc. of water, and the washings added to the 
filtrate. Ten cc. of the well-mixed liquid were taken up and 
neutralized with extreme care with a solution of sodium hydroxide 
(1:8), using phenolphthalein as an indicator whenever possible, 
and taking pains to leave the liquid very slightly acid rather than 
alkaline. ‘The liquid thus neutralized, or nearly neutralized, was 
* Entitled ‘‘ Testing for Mannose.” In Bulletin of the Bussey Institution, 
1902, 3. 13. 
+ I am greatly indebted to my colleague, Mr. Edmund Hersey, for the 
trouble he has taken to collect, from a small plantation on his estate at 
Hingham, samples of limbs from pine trees which should be as nearly as pos- 
sible comparable one with the others, though taken at different seasons and 
from different trees. Many other samples of woods and other materials were 
procured for me by Mr. Hersey and by other friends. 
