644 



THE INDIA RUBBER WORLD 



[September 1, 1915. 



with concentration of the alcohol, If boiled in absolute alcohol 

 to 20 per cent, oi its contained oxidized resinous 

 issolves completely in pure ether but is insoluble 

 in ether containing even a small amount of alcohol. It is partly 

 i spirits of turpentine, petroleum, olive oil and 

 phi esl iolvents are carbon bisulphide and chloroform. 

 nol cause it to swell, like caoutchouc, but solution 

 : the surface inward. These solvents give cloudy 

 solutions which on filtration are limpid and colorless. Evapora- 

 i thi solvent leaves the pure gutta percha as a 

 like body. 

 Ucohol precipitates cha from its solutions, 



and the inclusion of some of the solvent renders the 

 material somewhat tacky, particularly if benzene is the 

 nt. 



I mi UN M, PROPER riES 

 gutta percha of commerce, as already noted, 

 is not a simple substance, but a compound, or possibly 

 a mechanical mixture of several allied materials oc- 

 curring in more 

 or less varied 

 proportions, 

 cording to botan- 

 ical origin it 

 conditions of 

 ipulation . 

 We are in- 

 debted to Payen 

 for most of the 

 facts concerning 

 the chemistry of 

 gutta percha. 



Pure u u 1 1 a 



ha may be Figures Modelled from Gi cta. 



prepared by dis- 



solving the sample in carbon bisulphide, filtering, and evapo- 

 rating the solvent in the air on glass When purified in this way 

 ordinary commercial gutta percha showed, according to Miller: 



Pure gutta percha 7970 



Resins 15.10 



Vegetable fiber 2.18 



Water 2.50 



Ash 0.52 



100.00 

 Arpe demonstrated the presence of seven vari- 

 eties in the extracted resins. Their constitution is 

 unknown. Payen treated purified gutta percha 

 with cold alcohol, then In foiling alcohol, and 

 showed the presence of three distinct bodies: 1. 

 gutta (insoluble in cold alcohol and in boiling al- 

 cohol), 78 to S2 per cent.: 2. Iluavile (insoluble in 

 cold alcohol), 4 to 6 per cent.; 3, albane (solu- 

 ble in boiling alcohol i, 14 to 16 per cent. 



The separation 

 of 



these bodies is 

 effected by treat- 

 ing purified gutta 

 percha for several 

 hours with boiling 

 alcohol and filter- 

 ing. After stand- 

 ing one or two 

 days the alcoholic 

 solution deposits 

 considerable opa- 

 que granular mat- 

 ter. The granules 

 contain a nucleus 

 of fluavile, cov- 

 ered with a crystalline incrustation of albane. By repeatedly 

 washing this granular mass with cold alcohol the fluavile is dis- 

 solved and the albane remains. 

 Payen obtained pure gutta as a residue from boiling alcohol 

 tions < ludemans in 1858-59 investigated gutta fluavile and 

 albane, determining their properties and analysis. His results 

 are given as follows: Gutta is solid, pliable, extensible, but not 

 between 50 and 85 degrees Fahrenheit. It softens about 

 ahrenheit and assumes a dark brown coloration, 

 becoming more viscous and transparent as the heat increases. 



Trunk of a Gutta Tree with Hollow 

 Chisel. 



Sacred Cow 



At 212 to 230 degrees Fahrenheit it spreads into a soft paste, 

 and liquifies at 266 degrees Fahrenheit, beginning to boil at that 

 temperature, and distills into several hydroearbides, analogous 

 to those obtained from the distillation of rubber. In presence 



. ids, dilute alcohol, ether and chloroform, it behaves like 

 rubber. Pure gutta is insoluble in ether and light petroleum 

 spirit at ordinary temperatures, while fluavile and albane readily 

 dissolve. According to Arpe, gutta is not insoluble in ether un- 

 less previously treated with alcohol. Treatment with nitric acid 



es liberation of formic and hydrocyanic acids. In form of 

 powder it rapidly absorbs oxygen ; hydrochloric acid gas trans- 



