CHEMISTRY OF ¥001 
Part IX — Springwood and SummerwoodJ i 
By 
G. J. RITTER, Chemist 
and 
L. C. FLECK, Associate Chemist 
The purpose of the v;ork reported in this paper is to compare 
the chemical composition of springwood and summerwood in the annual 
rings of trees. 
Springwood differs from summerwood in physical appearance, 
type of cell structure, density, and thickness of cell trail. It was 
thought that analysis of the springv/ood and summeruood of representa- 
tive species might show characteristic differences in the chemical 
composition of the two "bands of growth and thus afford an additional 
means of classifying woods. The principal differences discovered were 
general, however, rather than individual. 
Preparation of Samples for Analysis 
In separating springwood from summerwood, it is most practic- 
able to cut the "bands from thin (3-mm. ) cross sections of wood having 
wide annual rings of growth. The width of the rings varies not only in 
different trees, but also during different periods in the history of the 
same tree. The latter condition makes it quite difficult to obtain 
suitable rings for springwood and summerwood samples representing a 
number of consecutive years in both the sapwood and heartwood of a 
tree. When suitable cross sections and areas of wood have been 
selected, the springv/ood and summerwood zones are split apart with 
a sharp wood chisel and removed separately. This material is ground 
and sieved to 80-100-mesh size. 
The methods of analysis are the same as described in the sixth 
paper of this series.— The results obtained for springwood and summer- 
wood of the 6 representative species chosen for study are recorded in 
the accompanying table. 
1 
Presented before the Cellulose Division of the American Chemical 
Society, Washington, L. 0. , April 1924. Fublished in Industrial 
&. Engineering Chemistry, 18: 608-9 (1926). 
2 
-Industrial & Engineering Chemistry, l4:1050 (1922). 
R950 
