448 Mr. G. Gore on the Properties of 



ing a heated brass we near to a very small portion of one end 

 of the bar, a sudden change or commotion of particles took place 

 throughout the mass, passing rapidly from the heated part to 

 the opposite end, attended by the production of a few very mi- 

 nute cracks, and with great evolution of heat, rapidly boiling a 

 few drops of water jilaced upon it. 



24'. And on another occasion, on accidentally touching a ca- 

 thode covered with perfect amorphous deposit against the anode, 

 the change with considerable hissing noise occurred, the electric 

 spark or current from the battery being in this case the apparent 

 exciting cause of the phaenomcnon. 



25. And, finally, with a rapidly-formed and perfect specimen 

 of dark antimony deposited upon a swinging helix of fine copper 

 wire, on washing it first in dilute hydrochloric acid and then in 

 water, and gently striking it with a piece of glass, it at once 

 shattered into small particles with considerable force, projecting 

 some of them to a distance of 10 feet, apparently by converting 

 into steam the adhering particles of water. 



26. This thermic property of amorphous antimony is retained 

 apparently unimpaired upwards of 2^ years; a piece deposited 

 in October 1854 evolved considerable heat by slight percussion 

 in May 1857. The change appears to be similar to the mole- 

 cular changes of sulphur, selenium, iodide of mercury, &c., ob- 

 served by llittorff, lleguault, Weber and others. I have laevcr 

 found that the phjenoraenon could be repeated with the same 

 specimen. 



27. The only observed exciting causes of the phfenomenon have 

 been ordinary heat, concentrated solar heat, friction, percussion, 

 fracture, and the voltaic spark. Heat appears alwcnjs to deter- 

 mine it, whilst, with thin deposits, slight percussion and even 

 fracture have frequently failed. Thick pieces will bear gentle 

 fiUng, but not violent fracture, at ordinary temperatures without 

 the change occurring. 



28. The production of the change and the rapidity of its action 

 are considerably dependent upon the temperature of the mass ; 

 pieces which would easily fracture without further change in cold 

 water would not break without change in the air at C0° Fahr. ; 

 the certainty and quickness of the action were also manifestly 

 greater when the metal had been previously warmed. 



29. Immersing the metal in water and gradually heating it to 

 212° Fahr. did not cause the change, destroy the property, or 

 have any material effect upon the rate of heating of the liquid. 

 Nor did sudden immersion in boiling water, or partial dis- 

 solving of the metal by warm aqua-regia, cause it, or destroy the 

 property; but slight percussion on removing it from the hot 

 •water caused it powerfully. 



