340 



FORESTRY INVESTIGATIONS U. S. DEPARTMENT OF AGRICULTURE. 











£hs 



2K 



3h 



4K 



.,..,. 









Fit*. 88 



-Relation skip oi different parts of same 

 disk 



does it represent equal pot turns of it in all samples. The numbers given in the column "water" are of course 

 suggestive as to the coinparath e degree of retention of moisture by the chtteient samples, since the latter were all 

 exposed to about the bame inlluenccs. But it seemed best to compare the amounts of volatile hydrocarbons and 

 rosin on wood free from that variable constituent; the moie so as some time elapsed between the analysis of the 

 first and last samples. 



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

 multiplied by 100, and means that foi every 100 parts of losm as many paits of the volatile hydrocarbons are found 



as is indicated in the column. This latio (~\ is of little value in cases when the amount of tuipentme is small, 



because a very small increase of the lirst constituent — an increase within experimental enor — will change the 

 quotient considerably. An inciease of 0.07 per cent of Aolatile hydrocarbons in 60. IV, Is will bring up 



T from 7.2 to 10. \ deciease of 0.07 per cent in 52, IV, 2s will change ^ from 25.20 to about 19. These numbers 



are therefore of very little significance when applied to the sap wood of all samples, to entire tree 52, and to some 

 parts of trees 00 and 1, all of which show only small portions of turpentine. 



DISCUSSION OF "RESULTS OBTAINED. 



Relation of rosin and volatile hydrocarbon to moisture. — Tlie 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, in 53 II, 17*,, 27*,, 37*; in 53 III, 17*., 27*,, 37* , 47*,; in 

 53 IV, 27*,, 37i, 47*,. The piece richest in oleoresin is generally 

 the poorest in moisture. But this is by no means 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. 

 Hap wood and heartwood. — 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 veiy rich trees, as in Nos. 53, 61, 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 17* is the richest, and the heartwood grows poorer as we approach the pith of the tree. 

 In a few cases, as in 1 III and in 1 IV, 17*, and 27*. are practically identical, while in some instances, 

 in 2 III, CI II, Gl III, and 53 II, 17*. is poorer than 2h. In nearly all cases the decline is marked 

 in 3hj and 47*. is usually found to be the poorest part of the disk. This relationship can be 

 rex^resented in a general way by the following curve: 

 Relation of volatile liydroeai bans 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. 



Pig 89 —Yield of volatile oil how constant quantity ot 



turpentine. 



