igoj] Herty — Pkoduction of Turpentine. 117 



across flattened surfaces of the tree and serve to lead the resin 

 to a central point. One of the gutters is slightly higher than 

 the other, delivering its resin into the lower gutter, from the 

 end of which all the resin drips into the cup suspended on a 

 nail just below. Such an apparatus can at the end of each 

 season be easily raised to a point near the scarification sur- 

 face. With this apparatus tests were made primarily of its 

 practicability and effectiveness. Further, the quality of the 

 resin exuding from the trees in successive years of operation 

 was determined. Under the "box'' system the resin of the 

 second, third and fourth years of operation shows gradually 

 increasing coloration and the rosin left after distillation of 

 the volatile spirits of turpentine is a deeper red and less valu- 

 able. With the cup and gutters placed near the freshly scarified 

 surface, it was proved that the quality of the resin so far as 

 concerns color is as good in the fourth as in the first year, the 

 color of the resin from the old "boxes" being due to absorp- 

 tion of the highly colored oxidized resin on the long surface 

 above the "box". Quantitative experiments were made upon 

 the loss of resin which falls outside of the "box", due to 

 trunks not perpendicular, and of the loss of volatile spirits of 

 turpentine during the long flow to the "box". It was also 

 shown that different portions of the circumference of a tree, 

 in many cases, vary greatly in ability to produce resin, and 

 that the underside of a leaning tree is much more productive 

 than the upper side. The daily rate of flow after scarifica- 

 tion was studied and it was found that in general, sixty per 

 cent, of the flow takes place during the first period of twenty- 

 four hours, twenty-five during the second and after seven 

 days, the flow practically ceases. Numerous other studies 

 were projected and some were partly carried out, but the sum- 

 mer vacation being ended, it was necessary to discontinue the 

 work in the field. 



The interest of the U. S. Bureau of Forestry was aroused 

 by these preliminary experiments and by the promise of praC" 



