— 55 — 



hard after prolonged exposure to air and sunlight. After giving some 

 details as to the manner in which the Chinese conduct the trade in 

 elemi, Bacon turns to the mode of collecting the gum. He states 

 that it flows in the trunk of the tree chiefly when the tree is begin- 

 ning to develop new leaves, and that in the principal place of produc- 

 tion, viz., Atimonan, in the district of Tayabas, this takes place about 

 January and June. During the rest of the year the tree is shedding 

 its leaves and yields no resin. For the purpose of collecting the balsam 

 the natives make incisions in the tree with tools known as bolos. The 

 resin then exudes from the cuts and collects on the bark, from which it is 

 removed once every few days, before it has grown dirty or hard. Bacon 

 concludes from his own examinations that healthy, full-grown trees are 

 capable of yielding annually 4 or 5 kilos of gum. One large tree 

 produced as much as 22 kilos in 2 months. The production of essential 

 oil from the various varieties of elemi, of different origin but of the 

 same botanical derivation, was carried out by distilling the fresh gum 

 in vacuo, separating the resultant oil from the water, drying with 

 chloride of calcium, and again distilling in vacuo, in which process 

 only the terpene fraction was considered, which was again distilled by 

 Bacon under ordinary pressure. Of 62 samples, taken from different 

 trees at Calaoag, in the district Tabayas, only two contained d-limonene: 

 b. p. 174 to 176° and 175 to 176,5°, <* D -[-89,0 and -}-96°, respec- 

 tively. The other samples contained phellandrene; their boiling points 

 varied from 168 to 179° and their rotation lay between -j- 134,5 

 and — 6o,6°. In dealing with this matter, Bacon describes as "phel- 

 landrene" a terpene which yields a crystalline nitrite, with a m. p. not 

 exceeding 1 2 1 °. The separate phellandrenes were mixed as follows : — 

 first the 6 laevorotatory samples («D30° — 30>3 to — 6o,6°), next, accord- 

 ing to the elevation of the b. p., the 17 samples with low b. p. (168 

 to 1 73°), then the 30 samples with intermediate b. p. (up to 175°), 

 and finally the five samples with the highest b. p. (175 to 179°). Out of 

 nine elemi oil terpenes from samples of resin taken at Gumaca, in the 

 Tayabas district, six contained d-limonene («© -f- 1 1 1,8 to -f- 117,9°), 

 two are alleged to have contained /?- phellandrene (b. p. 165 

 to 169° and 166 to 169°, « D _[_ 92,2° and -\- 90,7° respectively) and 

 one contained a-phellandrene (b. p. 173 to 175°, a p-f- 107,6°). As 

 Bacon appears to describe these two terpenes as "/?- phellandrene" 

 simply because of their low b. p., and as, moreover, he obtained from 

 a terpene which he regarded as pure /?- phellandrene a nitrite of 

 m. p. 121° (according to Wallach the two varieties of /S-phellandrene 

 nitrite melt at 102° and 97 to 98° respectively) while furthermore, 

 oxidation of the substance with permanganate yielded the aldehyde 

 phellandral, it would seem that more convincing proofs are needed 

 before the presence of the terpene referred to can be regarded as 



