340 



FORESTRY INVESTIGATIONS U. s. DKPAKTMKNT (>!' AGRICULTURE. 



Flo. 88 Relationship of different parts of same 

 rtisk- 



does it represent equal portions of it in all samples. The numbers j;iveii in the eolnnin "water" are of course 

 Hiij;j;e8tivo as to tlie comparative decree of retention of moisture by the different samples, since, the latter were all 

 exposed to about the same influences, lint it seemed kest lo compare the amounts of volatile hydrocarbons and 

 rosin on wood free from that variable constituent ; the more so as sometime elapsed between the analysis of the 

 liret and last samples. 



The last column in each table contains the ratio between the volatile hydrocarbons and rosin. This ratio i s 

 multiplied by 100, and means that for every 100 parts of rosin us many parts of the volatile hydrocarbons are found 



(I*i 

 I is of little value in cases when the amount of turpentine is small, 



lieeause a very small increase of the lirst constituent an increase within experimental error will change the 

 quotient considerably. An increase of 0.07 per cent of volatile hydrocarbons in (iO. IV, 1 will bring up 



T T 



from 7.2 to 10. A decrease of 0.07 per cent in 52, IV, '2s will change from L'.V-'H to about 111. These numbers 



h It 



are therefore of very little significance when applied to the sapwood of all samples, to entire tree 512, and to some 

 parts of trees (50 and 1, all of which show only small portions of turpentine. 



DISCUSSION OF RESULTS OBTAINED. 



Relation of rosin and volatile hydrocarbon to moisture. The amount of moisture retained by 

 different samples does not seem to have any direct relation to the amount of oleoresin in these 

 samples. Yet in the same tree, or rather in the different parts of the same disk, there seems to exist 



something like a relation of the two. This is especially notice- 

 able in tree No. 53. The moisture retained seems to vary in- 

 versely with the amount of oleoresin in the sample. Compare, 

 for example, iu 53 II, l/i, 2h, 3/(; in 53 III, I/*, L!//, 'Mi, 4th; in 

 53 IV, 2h, 3/i, 4/i. The piece richest in oleoresin is generally 

 the poorest in moisture. But this is by no ireans a universal 

 rule. Some trees show about the same per cent of moisture 

 in parts widely differing from each other in the amounts of 

 turpentine, and in many instances a smaller amount of tur- 

 pentine is associated with a smaller per cent of moisture. 



Sapwood and hcartwood. All the analyses, detail and average, show conclusively that the 

 sapwood is comparatively very poor in turpentine; it is immaterial whether it co:i:es from a rich 

 tree or a poor one, from a tapped tree or an untapped one. The turpentine in sapwood reaches 

 3 to 4 per cent in very rich trees, as in Nos. 53, 61 j and 2; in the remaining trees it is 2 to 3 per 

 cent. Consequently the results obtained for sapwood are not taken into account in the following 

 paragraphs. When differences between trees are spoken of, it applies entirely to heartwood. 



The different parts of the same disk show a constant relation in nearly all instances. In 

 most cases l/i is the richest, and the heartwood grows poorer as we approach the pith of tlie tree. 

 In a few cases, as in 1 III and in 1 IV, 1/t and 1h are practically identical, while in some instances, 

 in 2 III, 01 II, 61 III, and 53 II, 1/t is poorer than 2li. In nearly all cases the decline is marked 

 in 3/i, and ih is usually found to be the poorest part of the disk. This relationship can be 

 represented in a general way by the following curve: 

 Relation of volatile hydrocarbons to rosin. As the 

 turpentine in the tree is a solution of rosin in an essen- 

 tial oil, it will follow that the richer a tree is in tur- 

 pentine the richer it will be in the constituents that go 

 to make up this mixture. One would also expect that 

 the ratio between the volatile hydrocarbons and rosin 

 would be tolerably constant in the different parts of 

 the same tree, but the results of analysis do not indi- 

 cate it. They show that this ratio increases with the 

 amount of rosin. A part of heartwood having twice as much rosin as another part will contain 

 more than twice as much volatile products as the second part. This is true in a general sense 

 of parts of the same disk, of parts of different disks in the same tree, and parts from different 

 trees. There is no distinction in that respect between bled and unbled trees. This relationship 

 can be, formulated in the following way: The crude turpentine from heartwood rich in oleoresin 

 will yield a comparatively larger amount of turpentine oil than the turpentine from heartwood 

 poor in oleoresin. 



3h 



Flc;. 8i> Yield of volatile oil from roiiataut quantity of 

 turpentine. 



