304 



XL " On the Properties of Electro-deposited Antimony" (con- 

 tinued). By GEORGE GORE, Esq. Communicated by 

 Dr. TYNDALL. Received June 1, 1858. 



(Abstract.) 



In this paper the following additional information is given respect- 

 ing this singular substance. 



The change observed in it is shown not to be an exercise of the 

 force of cohesion, because the amount of heat evolved by the powdered 

 metal is not sensibly different from that set free by the substance in 

 its coherent massive state. 



The thermic discharge is not limited to a particular temperature, 

 but commences between 170 and 190 Fahr., and increases in rapi- 

 dity to some point above 212 Fahr., when it becomes sudden. 



The heat may be discharged either suddenly or gradually, accord- 

 ing to the amount to be discharged in relation to the amount of 

 cooling influences present. 



The specific heat of the unchanged metal was found to be= 

 0*06312; and of the same specimens, after being gradually dis- 

 charged, the specific heat was not sensibly different. But the spe- 

 cific heat of the substance, after sudden discharge, was found to 

 be=0'0543. 



The total amount of heat evolved by the substance during its 

 change was sufficient to raise the temperature of its own weight of 

 ordinary antimony (sp. heat= 0*0508) about 650 Fahr. 



The evolution of vapour which generally occurs during the change 

 is a result of the molecular heat acting upon the terchloride of anti- 

 mony contained in the substance. It occurs when a sufficient tem- 

 perature is produced either by internal or external causes, and does 

 not occur when the molecular discharge is gradual and the tempe- 

 rature is not sufficiently raised ; in such cases the weight of the sub- 

 stance remains unaltered. 



The substance, as usually produced from ordinary muriate of anti- 

 mony, or from a mixture of that substance and tartar-emetic, contains 

 small quantities of nearly all the ingredients and impurities of the 

 depositing liquid. 



The pure substance deposited upon sheets of platinum, in a solu- 

 tion of pure hydrochloric acid three-fourths saturated with pure 



