RESINOUS CONTENTS OK PINE. 



analyses fully substantiated Dr. Gomberg's work, so that it was safe to announce tlial : (1) IJIcd 

 timber is as strong as unbled timber; and (-!) tliat it contains tlie resinous substances in (lie same 

 amounts and similarly distributed as the wood of uubled timber, so that it seemed to follow as a 

 simple corollary that bled timber is also as durable as uubled, and hence equal to the latter in 

 every respect. 



The importance of this fact was quite fully realized. Traiitwiue, in his standard work, the 

 Engineers' I'ockctbook, at once placed the fact on eminent record, and the lumbermen of the 

 South, as well as all trades journals, spread the welcome news in every paper and at every 

 opportunity. 



The work of Mr. Gombcrg in determining the distribution of the resin through the different 

 parts of the tree is unique in method and classical in its clear scientific procedure and statement. 

 Since the publication in which it first appeared was at once exhausted, it appears proper to repro- 

 duce it in full, leaving out only a few tables, as a part of the most valuable work in timber physics 

 performed under direction of the Division of Forestry: 



A CHEMICAL STUDY OF THE RESINOUS CONTENTS AND THEIR DISTRIBUTION IN TREES OF 



THE LONGLEAF PlNE BEFORE AND AFTER TAPPING FOR TURPENTINE. 



[By M. CiOMliERG.] 



Botanists tell us that resins are produced by the disorganization of cell walls and by the. 

 breaking down of starch grannies of cells. Chemists believe that resins are oxidation products of 

 volatile oils, the change being expressed by formula as follows: 2Ci()Ili,i+30=C> ( ,II. tJ O 2 +H 2 O. 



Whatever view be correct, 1 one thing is certain, and that is that the formation of either resins 

 or essential oils requires the presence in the tree of those peculiar conditions which we call vital. 

 The tree must live, must be active, must assimilate carbon dioxide and imbibe moisture, in order 

 that oil of turpentine and rosin be formed. 



The heart of the tree is the dead part of it. It does not manufacture any turpentine. A part 

 of the oleoresin in it had been formed when the heartwood was yet sapwood, and remained there 

 after the change from sap to heart had taken place. It is also probable that the heart of the tree 

 acts as a storehouse in which there is deposited a portion of the oleoresin formed in the leaves 

 and sap. 



When a tree is tapped for turpentine there are two possible changes that might be supposed 

 to take place: (1) The tree may be considered as placed in a pathological condition, when it will 

 strive to produce a larger amount of oleoresin in order to supply the amount removed. In a few 

 years the energy of the tree will be exhausted and the ainouut freshly supplied will fall far below 

 the amount of oleoresiu drawn off by the tapping. The tapping will then have to be discontinued. 

 The oleoresin in the heartwood will in this ease remain untouched. (2) The oleoresiu previously 

 stored away in the heart might, by some unknown means and ways, also be directed toward the 

 wound. 



If the first change takes place then, the tapping will have little effect upon the chemical 

 composition of the heartwood. If, however, the second condition prevails during tapping, then 

 of course the heartwood will be seriously affected for some time after tapping, and will contain a 

 much smaller amount of oleoresin than it contained before tapping. Moreover, the tapping may 

 affect not only the amount of oleoresiu, but also the quality of the new product and the relative 

 distribution of volatile products. 



For this reason the chemical side of the problem has been approached by parallel analyses of 

 tapped or untapped trees for their relative amounts of turpentine. It was hoped that by a large 

 series of analyses an average might be obtained showing whether tapped and untapped trees differ 

 from each other in that respect. 



CHEMICAL COMPOSITION OF TURPENTINE. 



Under the name of turpeutine is known an oleoresiuous juice produced by all the coniferous 

 trees in greater or less amount. It is found in the wood, bark, leaves, and other parts of the 

 trees. It flows freely as a thick juice from the incisions in the bark. It consists of resin or resins 



1 The one view does not exclude the other. 



