GOODYEAR ON GUM-ELASTIC. 



by destructive distillation similar products to caoutchouc ; like 

 caoutchouc it is soluble in coal naptha, in caoutchoucine, and 

 in ether, and insoluble in water and alcohol." Then follows a 

 quotation from Dr. Maclagan's communication to the Scottish 

 Society of Arts : — " When placed in water at 110°, no effect 

 is produced upon it, except that it receives the impression of 

 the nail more readily, but when the temperature is raised to 

 145°, or upwards, it gradually becomes so soft and pliant as to 

 be capable of being moulded into any form, or of being rolled 

 out into long pieces or flat plates. When in the soft state it 

 possesses all the elasticity of common India rubber, but it does 

 not retain this property long. It soon begins again to grow 

 hard, and in a short time, varying according to the temperature 

 and the size of the piece operated upon, regains its original 

 hardness and rigidity." 

 Auorust 31, 1847. 



As Gutta Percha appears to be destined to become useful, as 

 a variety of caoutchouc, in its vulcanized state, particularly in 

 the form of hard compounds, the reader will perhaps find the 

 following extracts from the "American Journal of Arts and 

 Sciences," commonly called " Siiliman's Journal," interesting, 

 as giving a sketch of the history of the introduction of Gutta 

 Percha into the manufactures and uses of the civilized world. 



The first mention of Gutta Percha in Siiliman's Journal, is in 

 vol. 5, second series, page 289, (1847,) being an extract from 

 the Lond. Jour. Bot., No. 61, Jan., 1847, p. 33. 



This article attributes the discovery of the valuable prop- 

 erties of the substance to Mr. Thomas Lobb, when in Sintra- 

 pore, &:c., &c. 



Plant called Sapotaceous and Bassia is given as the name. 



It states that Dr. Montgomerie first brought Gutta Percha 

 into public notice. " He writes thus in the Magazine of 

 Science, 1845, &c., &c. ; — so long ago as 1822, when I was at 



