Schorger—Chemistry of American Conifers. 
759 
with NaOH as well as the subsequent addition of NaOH to the 
sulphite solution causes an attack of the cellulose resulting in 
a lower yield. Both these observations have been confirmed. 
Since solutions of sodium sulphite have a decidedly alkaline 
reaction as a result of hydrolysis, there was a possibility that 
even the sodium sulphite attacked the cellulose. This was 
found to be the case since when the solution was kept saturated 
with sulphur dioxide during heating the yield of cellulose was 
increased 1-2% in some cases. 
The chlorination was limited to 30 minute periods since in 
many cases a first chlorination lasting one hour as usually recom¬ 
mended is too long. The length of time and manner of heat¬ 
ing the sulphite solutions was also fixed to 30 minutes heating 
in a water bath. Renker recommends heating the sulphite 
solution on the steam bath for 4 ‘ 1 to 2 hours. ’ ’ On account 
of the alkaline reaction of the sodium sulphite, the period of 
heating should be as short as possible. 
The conifers are much more resistant to the action of chlorine 
than the broad-leaved trees, showing that there is a difference 
in the lignin. The lignin of the conifers contains fewer meth- 
oxy groups' and gives less acetic acid on hydrolysis. There is 
also a wide difference in the pentosan content of the two classes 
of woods. Yellow birch, for example, contains four times the 
amount of pentosan found in Douglas fir. As previously men¬ 
tioned the cellulose from the various species give about the 
same amount of furfural as the original woods. 
When the percentage of cellulose is based on the wood free 
from materials soluble in hot water and ether the following is 
obtained. 
Western larch 
66.40' 
Longleaf pine 
67.20 
Douglas fir 
66.30 
Mean 65.92 
White spruce 
63.79 
Sugar maple 
63.43 
] 
Yellow birch 
64.38 
y Mean 64.26 
Basswood 
64.97 
J 
The conifers accordingly contain a slightly greater amount of 
cellulose. 
