RUBBER PLANTING 215 



hydrochloric acid. The last named method of prepara- 

 tion confirmed a previous discovery by Bouchardet. 



The production of rubber from isoprene is a process 

 of polymerisation , that is to say the union of a number 

 of molecules each possessing the same empyrical formula^ 

 i.e. containing the same relative number of carbon and 

 hydrogen atoms. Analysis has shown that rubber con- 

 tains carbon and hydrogen in the same proportions 

 as exist in isoprene and turpentine. A study of the 

 compounds of rubber, particularly those with ozone, has 

 led Harries to represent the polymerisation of isoprene 

 in the following manner: 



/H, 



_ r* 



II II " \ ^ CH 



H C C CH 3 ^C C ' 



I + I =1 8 



C H 3 -C C-H " c < 



\ 



H 2 =C C=H, 



The actual molecule of rubber is probably a polymer 

 of the substance whose constitution is represented 

 above, and may consist of a number of similar eight- 

 ring molecules linked together. The empyrical formula 

 of rubber is thus C 10 H 16 , which is identical with those of 

 turpentine and gutta-percha. The molecule of the latter 

 is probably even more complex than that of rubber, but 

 may possibly be a higher polymer of the same series. 

 It should be observed that the account here given of 



