De. R. D. Thomson's ExamincaUm of the Cawdie Pine Resiru 129 



DAMMARONE. 

 When dammara rosin is finclj pounded and mixed intimately with 

 five or six times its weight of quick-lime, and the united powders are 

 distilled by the low heat of a spirit-lamp, either in a tube retort, or in 

 a larger vessel, if the quantity experimented on is more considerable, 

 dense white fumes speedily make their appearance, which condense in 

 the receiver first in the form of water, having an ethereal odor, and 

 gradually as a thick amber coloured oil which floats on the surface of 

 tho water. By the application of a heat of 300", tho water soon dis- 

 appears, 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 tho air, it becomes thicker. Its boiling point is above 

 270° F. It burns with a dense smoke, and is soluble in alcohol 



43 grs. gave when bunied with oxide of copper, 13*59 COi 

 and 4-4G5 grs. IIO. 

 This is equivalent to. 



Carbon, 86-22 



Hydrogen, 11.53 



Oxygen, 225 



100- 

 The result corresponds with the following calculation : — 

 Carbon, ... 38 X '75 =28-5 85-39 



Hydrogen, . . 31 X '125 = 3875 11-61 

 Oxygen, ... 1x1- =1* 300 



33-375 100-00 

 There is an excess of carbon in the analysis, which I believe to be 

 owing to the very great difficulty of separating the whole of the carbo- 

 hydrogen oil which forms tho basis of tho resin, and is disengaged in 

 the first stage of the distillation. All those who have made researches 

 on resins, are familiar with this obstacle to precise formulae. If we 

 compare this formula with that of dammaran, the action is pretty 

 obvious. 



Dammaran, . C^o Hsi 0« 



Dammarone, . C« IIsi O 



C, 05 = 2C0, + 



By this it appears that two atoms of carbonic acid have been 

 removed, and ono atom of oxygen ; that carbonic acid is fixed by the 

 lime, is proved by the effervescence of the residue in the retort on the 

 addition of an acid. The cause of the disappearance of the oxygen is 

 not so clear ; and I therefore prefer the following formula, where the 

 removal of the oxygen is accounted for :-^ 



