Dr. R. D. Thomson on the Cowdie Pine Resin. 87 



varnish. Copal in its natural state is insoluble in oil of tur- 

 pentine ; but when fused and boiled until water is removed, 

 the residual oil (Copalol?) is soluble in that menstruum. The 

 nature of the product from the distillation of resins depends 

 on the temperature. From a mixture of oils procured by di- 

 stilling common resin at a high temperature I have obtained a 

 considerable proportion of creasote. 



Dammarone. 

 When dammara resin is finely pounded and mixed inti- 

 mately with 5 or 6 times its weight of quicklime, and the 

 united powders are distilled by the heat of a spirit-lamp care- 

 fully, either in a tube retort or in a larger vessel, if the quan- 

 tity experimented on is more considerable, dense white fumes 

 speedily make their appearance, which condense in the re- 

 ceiver first in the form of water, having an aethereal odour, 

 and gradually as a thick amber-coloured oil, which floats on the 

 surface of the water. By the application of heat the water 

 soon disappears, while a dark oil remains, which may be 

 further purified by rectification. This oil is exceedingly 

 liquid when hot, but on cooling and exposure to the air it be- 

 comes thicker. Its boiling point is above 270° F. It burns 

 with a dense smoke, and is soluble in alcohol. 



4*3 grs. gave when burned with oxide of copper 13*59 C0 2 

 and 4-465 grs. HO. 

 This is equivalent to 



Carbon 86*22 



Hydrogen 11*53 



Oxygen 2*25 



100- 

 This corresponds nearly with 



Carbon .... 38 x '15 = 28*5 85*64 



Hydrogen . . 30 x '125= 3*75 11*27 

 Oxygen .... lxl* ■ 1' 3*09 



33*25 100*00 

 The comparative formula will then be 

 Dammaran . . C 40 H 31 6 

 Dammarone . . C 38 H 30 O 



~~2 I 5 = 2 C0 2 + HO. 

 The experimental result gives a larger amount of carbon, 

 which I believe to be owing to the difficulty of separating the 

 whole of the carbo-hydrogen oil which forms the basis of the 

 resin, and is disengaged in the first stage of the distillation. 

 All those who are familiar with this branch of chemistry are 

 aware of this obstacle to precise formulas. The experiment 



