CERTIFICATE OF PROFS. BOOTH AND BOYE. 81 



PROFS. BOOTH AND BOYE'S REPORT. 



METALLIC OR VULCANIZED GUM-ELASTIC. 



COPY. 



Philadelphia, Dec. 18, 1844. 

 To Mr. Charles Goodyear. 

 Dear Sir, 



Having completed a series of experiments upon the Metallic 

 Gum-Elastic Composition, we submit to you a report of our 

 conclusions deduced from the same ; merely premising that the 

 conclusions agree so closely with the results attained by us, in 

 researches on the same material some tioo years since, the re- 

 marks are wholly applicable to both series of experiments. The 

 experiments instituted were both mechanical and chemical. 



1st. Chemical tests. 



This composition differs remarkably from common gum-elas- 

 tic in its chemical behavior. 



By the application of degrees of heat at which organic sub- 

 stances are very much injured or destroyed, it remains un- 

 affected, and requires an unusually high temperature to soften 

 it ; about the same, it would appear, as causes it to inflame. 



It resists, in a powerful manner, those chemical agents which 

 rapidly destroy, dissolve, or soften common gum-elastic. Long 

 continued immersion in the usual solvents of gum-elastic, does 

 not produce solution ; a shorter period of contact or immersion 

 seems to have no effect upon it. 



Strong oil of vitriol and nitric acid char it only after con- 

 tinued contact ; a shorter time of immersion, or somewhat diluted 

 acids, produces no effect. Boiling water and alkaline liquids 

 produce no effect upon it, unless the latter be very concentrated 

 and boiling, and even then the effect is a trifling diminution of 

 its tenacity. 



It will be observed from the above behavior, that it resists 

 chemical tests in a manner superior to organic substances. 



