43 



It is evident that no constant relation, as to amounts of oleoresin, exists between the disks of the 

 same tree. 



Comparison of tree 52 with 53. — These two trees were both supposed to have been sound, 

 healthy trees at the time of felling, and yet they differ from each other as much as two trees could 

 differ. The heartwood of one is very rich in turpentine, that of the other contains comparatively 

 very small quantities, only a trace. How to explain this difference? Previous to felling they had 

 both been tapi)ed for four consecutive years, consequently both must have contained considera- 

 ble amounts of turpentine. Since the last tapping they stood for live years side by side, both 

 exposed to the same influences. This great difference can not be traced directly to tapping, for 

 tlie latter, it may be assumed, would have affected l)otli trees equally. The cause of the difference 

 between 53 and 52 ought to be looked for, rather, in the condition of the two trees before tapping. 

 In connection with this it would be interesting to know how much turpentine had each tree yielded 

 when tapped. 



Comparison of tree 60 irith 61. — There is a decided difference l>etween the two trees. The 

 highest numbers in 60 are 0.84 per cent for volatile hydrocarbons and 5.35 for I'osin, while in 61 

 0.75 and 5.67 are the lowest numbers for the corresponding constituents, the highest being 3.49 

 and 16.29, respectively. Here again we have two trees of about the same age, under apparently 

 tlie same conditions of growth, tapjied at the same time and abandoned for the same length of time 

 before felling, and yet differing very widely from each other. It is difficult to conceive why tap- 

 ping should have aff"ected the heartwood of these two trees in such a strikingly different manner. 

 If the assumption is made that the tapping had drained both trees equally, what explanation can 

 be given for the fact that within only one year of abandonment one tree is very lich in turpentine, 

 while the other has less than one- fourth as much? 



Comparison of trees 52 and 53 with (JO and 61. — Compare 53 and 01. Here we have two trees 

 both very rich in turpentine, but while 53 had five years of rest after tapping, 01 had only one 

 year. Had the tapping forced the trees to jiour out their oleoresin previously stt)red up in the 

 heart, we should expect to tind in the time of rest the prime factor for a tree in resuming its natural 

 condition. But, on the contrary, results of analysis show that time ol' abandonment before felling 

 is of little importance. While we can have a tree very rich in turpentine within Ave years after 

 tapping, we can also have trees rich and poor even within one year, and trees almost totally 

 deprived of turpentine in the heartwood within Ave years after tapping. 



Comparison of 1 with 2. — These two trees had never been tapped, and yet neither is rich in 

 turpentine. No. 2 contains about twice as much turpentine as No. 1, the difference becoming 

 smaller as we go up the tree. The highest niimbcivs for 2 are 1.93 and 14.10 for T and B, respec- 

 tively, the lowest O.SO and 5.89, with an average of about 1 and 7. We can say that there is as 

 much difference between untapped trees as there is between trees that have been tappied. 



Average anah/ses. — The average analyses cover 16 trees; 13 trees furnish 4 sets of analyses of 

 tapped trees, and 3 trees furnish 1 set of untapped. The results obtained are summarized in the 

 following table : 



These results show a pretty constant average number for turpentine in tapped trees. The 

 heartwood of untapped trees is poorer in both volatile oil and rosin than that of tapped trees. 

 And here again it is worthy of notice, that time of abandonment is of little importance to tapped 

 trees. The trees that had been abandoned for one year are fully as rich as those that had live years 

 to recover from tapping. 



Comparison of tapped with untapped trees. — If now the heartwood of tapped trees be com- 



