517 



Caoutchine. 



Himly's analysis was correct. The mean results of three analyses 

 are compared in the following Table with those of M. Himly : 



Mean. Himly. Calculation. 



>^^_ 



Carbon . . 88'1 88-44 C 20 120 88'2 



Hydrogen . 11-9 11'56 H 16 16 11-8 



136 100-0 



Two of the determinations, the results of which are incorporated 

 in the above mean, were made on a substance from gutta percha. 

 The vapour- density was : 



Experiment. Himly. Calculation = 4 vols. 



4-65 4-46 4-6986 



We now for the first time see the relation between the two hydro- 

 carbons. It is the same as between amylene and paramylene. The 

 author discusses the boiling-point of these bodies, and shows that 

 they form most decided exceptions to Kopp's empirical law. 



Action of Bromine on Caoutchine and its isomer Turpentine. 



Caoutchine and turpentine act on bromine in precisely the same 

 manner. One equivalent of the hydrocarbon decolorizes four equi- 

 valents of bromine. To determine this point quantitatively, eight 

 experiments were made, four with turpentine and four with caout- 

 chine. The quantity of bromine-water employed was 20 cub. cents. 

 =0*2527 gramme bromine. 



Mean of four turpentine experiments. Mean of four caoutchine experiments. 

 0-1074 grm. 0-1091 grm. 



Conversion of Turpentine and Caoutchine into Cymole. 



By the alternate action of bromine and sodium on caoutchine or 

 turpentine, two equivalents of hydrogen are removed, the final result 

 being cymole, having exactly the odour hitherto considered charac- 

 teristic of the hydrocarbon obtained from oil of cumin, and quite 

 distinct from that of camphogene. The liquid was identified by the 

 annexed analyses. No. I. was from turpentine, II. and III. from 

 caoutchine. 



