TJNNINO, PLATING, &C. 



become paralylic, as is the case also with thu:-o ulio work in quick. 

 ?ih ermines ; this is not to he wondered at, if w<- na^ credit Mr. 

 L> yle, who assures us that mercury has been sevrral titnes found 

 in the heads of artificers exposed to its fumes*. In the Philoso- 

 phical Transactions +, then- is an account of a man, who having 

 ceased working in quicksilver for six months, had his body still 1-0 

 impregnated with it, that by putting a piece of copper into his 

 mouth, or rubbing it with his hands, it instantly acquired a silver 

 colour. This, though a surprising, is not a fact of a singular na. 

 ture ; it is well known that sulphur, taken inwardly, will blacken 

 silver which is carried in the pocket ; and 1 have somewhere read 

 of a man whose keys were rusted in his pocket ; from his having 

 taken, for a long time, large quantities of diluted acid of vitriol. 

 1 remember having seen, at Birmingham, a very stout man ren. 

 dered paralytic in the space of six months, by being employed in 

 fixing an amalgam of gold and quicksilver on copper ; he stood 

 before the mouth of a small oven strongly heated; the mercury was 

 converted into vapour, and that vapour was inhaled by him. A 

 kind of chimney, I believe, has of late been opfn^d at the farther 

 side of the oven, into which the mercurial vapour is driven, and 

 the health of the operator is attended to. The person I saw was 

 very sensible of the cause of his disorder, but had not courage to 

 withstand the temptation of high wages, which enabled him to con- 

 tinue in a state of intoxication for three days in the week, instead 

 of, what is the usual practice, two. 



[Bishop Watson. 



CHAP. VI. 



METALLIC PLANTS, OR TREES. 



BEFORE we quit the very curious and interesting subject of metals, 

 we may observe that many of these substances when minutely dis- 

 solved in a menstruum, and treated with a third substance that se- 

 parates them wholly or in part from the fluid in which they are 

 thus contained, crystallize into the appearances of very beautiful 



* Boy1e\ Works, vol. iii. p. 330. t 1665. 



