[ ^7 J 
LEAD. 
LEAD, which is the metal whofe denjity is 
next in order to that of gold, affords a glafs of the 
colour of the Hyacinth, a gem whofe diftinguifhing 
character is, that it is red with an admixture of 
yellow^ the fame colour which by writers in optics 
is called orange, 
1 . Lead, kept in fufion for a confiderable time, in 
a ftrong crucible and a very violent heat, is re- 
duced to a glafs of the colour of that gem 
2. Lead reduced to litharge, and melted with one 
third or fourth part of it's weight of fand, in a 
covered crucible, in a ftrong fire for two or 
three hours, unites with the fand into an orange- 
coloured glafs like the former [/J. 
3.. Glafs of Lead is mentioned by feveral authors, 
as a compofition proper, without the addi- 
tion of any other ingredient, for imitating the 
Hyacinth [wj. 
[/^] Flora Saturnizans, chap. ii. Henckel de approprla- 
tione, cap. ii. fedt. 4. 
[/J Junker, Confpe<El. Chem. tab. xix. p-. 434. 
Recipe Lithargyrii partes tres, arenae nitidas partem unam ; 
mifta imponantur forti tigillo ; per 3 circiter horas tenuiflime 
fundantur, quo fa£to malTam fluentem in calidum mortarium 
effunde, et habebis vltrum pcllucidum, Hyasinthini ferme coloris. 
[wjj Shaw’s Lectures, p. 299. 
Lead melted into glafs with fand Is the foundation of imitat- 
ing all the coloured gems : for this glafs itfeJf will referable the 
Hyacinth, &.C, 
Merret’s Notes to Ncri, chap, 61. 
Our author mentions not a Hyacinth from glafs of Lead. Bap. 
Porta fupplies you with it, I. vi. c. 7, in thefs words : To make 
Vol.lv. d silver. 
