RESULTS OF EXAMINATIONS. 27 



of its fractions were so treated, a copious precipitate of phellandrene 

 nitrite was obtained. After repeatedly dissolving in chloroform and 

 precipitating with methyl alcohol the nitrite melted at 90 when 

 slowly heated, and at 103 when heated rapidly. 



From the data obtained on fractionation it was thought that per- 

 haps both of- and /?-phellandrene were present. Wallach ' l states: 

 ",5-phellandrene appears to possess a somewhat lower boiling point 

 and higher specific gravity than <*-phellandrene." He shows, 

 also, the existence of an a- and /^-nitrite of n'-pheh'andrene, and 

 an a- and /^-nitrite of /?-phellandrene melting at 112 to 113 or 

 113 to 114, 105, 102, and 97 to 98, 2 respectively. These melt- 

 ing points were obtained by Wallach, through rapid heating. 

 Although the data in Table 5 and the curves of figures 1 and 2 

 indicate strongly that both forms of phellandrene are present, 

 in no case was it possible to obtain a nitrite of lower, or higher, 

 melting point from any of the fractions by solution of the nitrite 

 in acetone, and fractional precipitation with water, if the nitrite 

 was purified until perfectly white. Examination for limonene 

 also gave negative results. The oil must, therefore, consist largely 

 of /?-phellandrene. So far as known, this terpene has never before 

 been detected in the oil from the oleoresin of any member of the 

 genus Pinus. 



EXAMINATION OF THE ROSIN. 



The rosin was not completely soluble in 95 per cent alcohol. A 

 white curdy residue was obtained, which indicated the presence of 

 some of the oil that had been polymerized during distillation. In 

 appearance it is exactly like the polymerized residue from the dis- 

 tilled oil when digested with alcohol. The oil accordingly polymer- 

 izes with great readiness, for the distillation was conducted with 

 steam, and the temperature of 145 C. was not exceeded in drying 

 the rosin. 



The rosin, grade I, had the following properties: Specific gravity, 

 1.061; acid number, 131.2; saponification number, 139.6; ether num- 

 ber, 8.4. About 80 per cent of crude crystals in the form of trian- 

 gular plates, and melting at 155, were obtained by crystallization 

 from alcohol, diluted with concentrated HC1. After several crys- 

 tallizations from acetone the abietic acid melted at 159 to 160. 



For further confirmation, the silver salt of the abietic acid was 

 obtained and analyzed with the following results: 



Percent. 



0.2340 gram silver salt gave 0.0611 gram silver =26. 11 



.2470 gram silver salt gave .0647 gram silver =26.19 



Mean =26. 15 



Silver abietate, Ag(C 20 H 29 O 2 ), requires 26.37 per cent silver. 



i Annalen, pp. 42-43, vol. 336, 1904. Ibid., pp. 15 and 44. 



