

PROFESSOR gale's CERTIFICATE. 79 



INSCRIPTION ON A MEDAL OF THE FRANKLIN INSTITUTE, 

 PENNSYLVANIA, 1844. 



" Awarded to Charles Goodyear, for gum-elastic goods." 



PROF. L D GALE'S CERTIFICATE. 



ACID GAS PROCESS. 



I have made a course of experiments from information con- 

 fided to me by Mr. Charles Goodyear, in relation to his method 

 of the manufacture of India rubber, and have the satisfaction to 

 say, that the result has been perfectly successful. 



The gum, reduced to the consistence of stiff paste, by means 

 of common spirits of turpentine, which requires no purification, 

 is again restored to its original elasticity and imperviousness. 

 The viscous, or adhesive property which belongs to the gum in 

 its natural state, and which is increased by the solvents generally 

 used, has heretofore presented all the obstacles to the success of 

 the manufacture and uses of this article. The process of Mr. G. 

 by which this difficulty is removed, depends on chemical princi- 

 ples, which are fixed and invariable, and there seems to be no 

 possible obstacle to its practical application. 



L. D. Gale, 

 Prof. Chevi. N. Y. College Pharmacy, and Prof. Geology 

 and Mineralogy N. Y. University. 

 New York, Sept. 1, 1835. 



Note. — This certificate was given before the process was made public, to 

 sati.sfy the inquiries of private individuals. 



