BULLETIN OF THE BUSSEY INSTITUTION. 49 
In all the other experiments the tests were not confined to the 
unevaporated products of the hydrolyses, as above described, but 
similar methodical tests were made after the liquors had been 
evaporated. To this end the remainder of the acid filtrate — after 
the removal of the 10 cc. portion which had been abstracted for 
the foregoing tests—was carefully neutralized, or almost neutral- 
ized, with sodium hydroxide and evaporated over a water-bath 
to soft dryness. The residue was taken up with 10 cc. of water, 
the slightly acid solution was filtered, and the filter rinsed with 
1 cc. of water which was added to the filtrate. One cc. fractions 
of the liquid thus obtained were diluted and tested precisely as 
described above, with the exception that 16 drops of the phenyl- 
hydrazin acetate reagent were added to each fraction, instead of 
the 12 drops used before, on the ground that a larger amount of 
mannose should naturally be expected to be present in the evap- 
orated products than in the unevaporated. Here, again, the pre- 
cipitates were examined under the microscope after two hours, 
and subsequently, if need were, at intervals during forty-eight 
hours. The results obtained by this methodical, progressive 
system of diluting and testing are set forth in the following table, 
where the words ‘** Yes” and ‘‘ No” mean that mannose was or 
was not detected : — 
The pine needles and bark mentioned in the table were obtained as follows : 
White pine needles plucked from a tree at Hingham, Mass., on De- 
cember 18, 1902. 
White pine needles plucked from a tree at Hingham, Mass., on Feb- 
ruary 15, 1908. 
Fresh needles of the white pine, plucked from the tree June 10, 1902. 
The average length of these needles was 2.5 inches. 
Old needles of the white pine shaken from the tree on June 5, 1902. 
Dead needles of the white pine that had fallen from the tree in the 
spring of 1902. They were picked up from the ground beneath the 
tree on June 5, 1902. 
Bark from the limb of the white pine tree cut August 9, 1902. 
It is to be remembered that mannan had already been detected in this 
laboratory in the wood of certain other coniferous trees beside the white pine, 
viz., in the wood of the pitch pine (P. stgida), the Norway spruce (Picea 
excelsa), the hemlock spruce (7’suga Canadensis), the Japanese larch (Lari 
leptolepis). the red cedar (Juniperus Virginiana), and the white cedar 
(Chamecyparis spheroidea), as has been set forth ip Volume III, page 32, 
of this Bulletin. 
