4 Mr. Daniell on the Action of Mercury 



some of them had the appearance of being partly imbedded 

 in the bar, or dissected from its substance. They were of a 

 darker hue, and more brilliant than the crystals from lead and 

 tin. 



EXPERIMENT V. 



A bar of fine silver was partly immersed in mercury, as in 

 the preceding cases : at the expiration of a fortnight no crystals 

 had been formed. The mercury had entered into its substance, 

 but upon trial it had not lost its malleability. It was replaced, 

 and at the end of six weeks had not apparently changed its 

 characters. The test-tube, with its contents, was now heated 

 till the mercury began to boil, and was set by to cool gradu- 

 ally. In twenty-four hours' time the bar was again examined, 

 and a bundle of very fine needle-crystals was found clustered 

 round the part which was just intersected by the surface of the 

 liquid. 



In this case, the affinity of the mercury for the silver enabled 

 it to penetrate its pores, and thoroughly to saturate it, but its 

 attraction for the resulting compound was not sufficiently 

 strong to allow it to overcome the remaining attraction of 

 aggregation, and dissolve the solid at the ordinary temperature 

 of the air. When assisted, however, by heat, the solution 

 was effected, and the compound, as in the former instances, 

 being specifically lighter than the pure fluid, floated to the top, 

 and crystallized. 



EXPERIMENT VI. 



A small portion of a bar of fine gold, about an inch and a 

 half in length, was put into mercury, in which, of course, it 

 sank, from its greater specific gravity. The fluid very quickly 

 penetrated it, and completely destroyed its yellow colour. In 

 a month's time it retained its malleability, and a part of it was 

 flattened under the hammer into a very thin plate. Its sur- 

 face was studded with very minute crystals, whose dimensions 

 were too small to be determined. The gold was then heated 

 in the mercury to the boiling point of the latter, when it was 

 completely dissolved, and a pasty amalgam formed. 



There can be no doubt tlaat in all these instances the mer- 



