Mercury. i^-j

lead seems to come out of it in equal timesof agitation, and consequently the wholebecomes pure at once. Also, whereas,while the lead was in the mercury, it felt,as I may fay, like soft clay, the momentthe lead is separated from it, it begins torattle as it is shaken, so that any person inthe room may perceive when it has beenagitated enough. *

That the mercury is made quite pure bythis process I ascertained by distillation.For having distilled in a glass vessel a largequantity of quicksilver, in which both leadand tin had been purposely dissolved, andwhich had only been agitated in this man-ner afterwards, I found nothing more thana light whitish stain on the bottom of theretort.

When

* Pure mercury may also be distinguished from thatwhich is very impure by this circumstance, viz. that amixture of lead or tin, at least, very much diminishes itsattraction of cohesion. For, when pure mercury is con-tained in a glass or earthen vessel, there will be a hollowspace between the metal and the vessel; whereas if therebe lead or tin in it, the whole surface, even to the place ofcontact with the vessel, will he perfectly level.

- 3