INVESTIGATIONS INTO RESINS. 



339 



Another sample gave: 



The results would indicate that the distillation is practically complete at 160, and that Jie 

 wood itself does not contribute any CO, by partial decomposion at that high temperature; for, 

 should the latter be the case, higher results might be expected at ISO than at 1(50, and then the 

 sapwood would give much higher numbers for turpentine oil than those actually obtained. 



Even if this method does not give the absolute amounts of volatile hydrocarbons, yet it 

 certainly gives results very near the truth, and, what is more important, under the same conditions 

 it gives constant results. Therefore, by employing strictly parallel conditions in the analysis of 

 the different samples, results are obtained which can be safely used as indices of comparison 

 of the relative amounts of volatile hydrocarbons in the samples under analysis. 



MATKItl.U. roll ANALYSIS AND .METHOD OK DESIGNATION. 



Material*. Trees No. 52 and 53, abandoned five years. 



Trees No. 60 and 61, abandoned one year. 



Trees No. 1 and 2, not tapped. 



Trees 54-57, abandoned five years. 



Trees 58-59, abandoned five years. 



Trees 63-65, abandoned one year. 



Trees 66-69, abandoned one year. 



Trees 17-19, not tapped. 

 Generally Disk II is 23 feet from ground. 

 Disk III is 33 feet from ground. 

 Disk IV is 43 feet from ground. 



Method of designation. It was thought best to make a somewhat detailed analysis of a few 

 bled and nnbled trees in order to gain an insight into the quantitative distribution of turpentine 

 in the trees. Each disk was divided into pieces of about thirty rings each, the heart and sapwood 

 being kept separate. The number of the disk is designated by a roman figure, the kind of wood 

 by either s for sapwood or h for heartwood. The arabic figure which precedes the h or s designates 

 the number of the piece, counting for the sapwood 

 from, the bark; for the heartwood, from the line of 

 division between sap and heart. 



Preparation of material. The first six tables 

 give the results of what might be called "detail" 

 analysis, where each piece of about thirty riugs has 

 been analyzed separately. The material for analy- 

 sis was prepared in the following way: A radial 

 section of the disk, about 1 to 2 iuches thick, is 

 selected. A piece of 1 inch is cut off' transversely, 

 and the strip is then divided into pieces of about 



thirty rings each. From the freshly cut transverse surface about 15 grams of thin shavings are 

 planed off and placed in a stoppered bottle. The exact amount used for analysis, usually from 3 

 to 5 grams, is found by weighing the bottle before and after taking out the portion for analysis. 



The second set of tables, VII to XII, inclusive, give the results of "average" analysis. The 

 material for these analyses was obtained by mixing equal quantities of shavings from the corre- 

 sponding portions of several trees and taking for analysis an average sample of the mixture. The 

 sapwood furnish one analysis and the heart wood was either analyzed as a whole or divided into 

 portions, Ih and 2/i, if of considerable thickness. 



NOTKS ON TAKI.ES 1 TO XII. 



Each table contains a column "calculated for wood free from moisture/' giving the per cent of volatile hydro- 

 carbons and rosin obtained by calculation from results actually found. Object ions might be raised to this mode fff 

 interpreting the. results. It might In- said that the moisture in the wood can not be disregarded, because it is as 

 miu-h an essential ]iro-:ima!o constituent of ood as the turpentine itself is. Hut since the analyses were not inaile 

 soon after the trees had bec.i felled, the moisture fouiid in the samples does not represent the original moisture, nor 



FIG. 87. DistriUutiou of turpentine in trtt-s. (A piece marked 

 52 III 2/t nicaiiB tree No. 52, disk III, the second piece of the 

 heart.) 



