MANNAN CONTENT OF THE GYMNOSPERMS 



201 



A longleaf pine tree 120 years old and 53 feet tall was felled in 

 Mississippi in July. Small disks were cut from the trunk at the 

 distances 2, 22, and 45 feet respectively from the ground, and their 

 mannan content determined as follows : 



a For entire disk, heartwood and sapwood being indistinguishable. 



The results obtained indicate that there is more mannan in the 

 sapwood than in the heartwood, and that the mannan decreases 

 progressively from the base of the tree upwards. 



A radial section of a sugar pine log having a diameter of nearly 

 four feet was divided into six parts and analyzed to determine if 

 the mannan content varied appreciably from the center of the tree 

 to the circumference. The results are given in Figure 1. The mannan 



/f/7/76/a/ /?//7^S 



/S4 ; 76 \ -^6 



Fig. 1. — Mannan Content of Radial Section of Sugar Pine. 



is uniformly distributed throughout the heartwood but decreases in 

 the sapwood. The figure for the sapwood is the result of three de- 

 terminations. This is the only exception observed to the general rule 

 that the sapwood contains more mannan than the heartwood. This 

 generalization is supported by the results from samples Nos. 9, 12, and 

 18, Table 1, and disks Nos. 1 and 2, Table 2. This suggests the possi- 

 bility of obtaining considerably larger yields of ethyl alcohol from 

 slabs and edgings than from mill-run sawdust. 



