408 BULLETIN OF THE BUSSEY INSTITUTION. 
The Outer Wood of a Gray Birch Tree felled in October contained 
(dry at LOO° C.) per cent of, 
‘eStarch@. (by malts. Atty 68,011) oy ape on i reek 
Pentosans shown by hydro- Pentosans shiner by furs 
chloric acid of 1%, less furol in residue from 
BOL OL MBECN sa? cael Ose action of malt .. . . . 32.66 
Pentosans shown by furfurol 
in residue from action of 
AE SS Be tse . 23.70 
Cellulose (by KHO), after 
subtraction of pentosans 
found in the crude fibre. . 43.83... 3 
vba Gi pee Ty eee 0) O86 SL 
Albuminoids(N [0. 52] X6. 25) (3.25 +05 otis bs ie 
Fat (ether-extract).. . .', + 2.58 °. ». 5.95 jis nee 
‘*Lignic acids” * and other 
undertermined matters, 
4.€.,°* loss” . . . we « « 14.08. 2). 0) 9 
100.00 100.00 
* Notr. — It is of interest to remark that Lange ¢ found 12% and 14% of his 
‘‘lignic acids”? in beech wood and oak wood respectively. Though from the 
severe chemical treatment (fusion with caustic potash) to which these substan- 
ces have been subjected, it is to be suspected that they are in some degree 
products of the decomposition of matters in the wood rather than actual con- 
stituents of the original wood, it is to be noted none the less that the lignic 
acids of Lange, like the old ‘‘ lignin” of several earlier experimenters, contain 
a higher percentage of carbon than is contained either in cellulose or in xylan, 
whence the conclusion that they are derived from another ‘‘ encrusting mat- 
ter” than xylan. Unfortunately, much confusion still prevails as to the use 
of the word lignin which was often applied formerly to a mixture of lignic 
acids and xylan, or even in some instances to xylan alone. Thus, as a basis 
for the perplexing statement of some authors that wood may consist to the 
_ extent of one-half or one-third its weight of ‘‘ lignin,” it seems plain that xylan 
and lignic acids must have been counted in together. 
I am indebted to my assistant, Mr. J. M. Tilden, for much 
help in carrying out the details of this research. 
+ Zeitschrift fiir physiologische Chemie. 1890, 14, 26. 
a 
