134 Journal of the Mitchell Society [^December 



the oleoresins were collected from these at regular periods of 

 four weeks until the close of the season in the fall. From li^e 

 resins prepared from these specimens the following results were 

 obtained : 



Table IV. 



Per cent, resene In resin from 



It is scarcely probable that in the case of Pinus Palustris any 

 significance is to be attached to the gradual increase in the per 

 cent, of resene as the season advanced until the last collection. 



Further determinations were made of the per cent, of resene 

 in specimens of oleoresin collected with great care in Florida 

 and promptly analyzed. The following results were obtained: 



Tree 

 Kb. 



I 

 2 



3 



Finally, a specimen of " scrape " (Gum Thus) was obtained 

 from a Longleaf pine (Pinus Palustris). This scrape is the 

 hardened mass which gradually collects on the scarified surface 

 of the tree as a result of the crystallization of the resin acids of 

 the oleoresin. It receives its name from the fact that at the end 

 of the season it is scraped from the surface of the trees by means 

 of a sharp tool. It contains approximately one-half as much 

 spirits of turpentine as the ordinary oleoresin collected from the 

 receptacles. The resin was prepared from this scrape by distil- 

 lation with steam as above. On analysis it showed 3.14 per 

 cent, of resene. 



In continuation of this work, there is now being carried out 

 in this laboratory an investigation of the composition of the 

 resene of Pinus Heterophylla. 



University oe North Carolina, 



