2^4- 0« ^'■''^ Pi'cparaiio7i of AinheT Varyrijl:, 



of it remains unmelted, it will not be ciiflblved by the var- 

 ni(h ; and if the operation be pei formed with a continued 

 and (Irong heat, it will be burnt and unfit for ufe. 



When the amber is kept over a weak fire it will not 

 melt, but becomes a fort of blackifli brown incruftation, 

 which alfo may be employed for varniOi provided it has not 

 been too much or too little evaporated : it will be in the beft 

 condition when von obtain half a pound from a pound. li 

 the amber is too little evaporated, it muft be again put into 

 the pan till it be reduced to the proper weight. The fame 

 thing is to be obferved when you melt it ; but the parts which 

 are not fufed muft be picked out, in order to be afterwards 

 alfo melted. 



I have found that a pan with a flat bottom is better than 

 one with a round bottom, becaufe the melting or evapora- 

 tion is effefted fooner in the former than in the Inttcr ; for 

 jn the latter the amber lies thick in the middle, and is burnt 

 at the bottom and fides before it can be brought to melt or 

 evaporate. 



It is not necefPary, for making varnifli, to pick out pure 

 and tranfparent amber, but only the common yellow fmall 

 fran;ments, which may be procured for h;j!f the price of that 

 in lumps. The earthy part, which is found in amber not of 

 the cleareft kind, feparates itfelf from the warm varnlfli when 

 jt is fuffered to ftand fonic time before it is decanted. 



Method of priparhig IJiifecd-Cil Varn'ijh. 



One poimd of well pulveri fed and fiftcd litharge, four ouncesi 

 of finely pounded wl lite vitriol, and one quart of linfeed oil. 

 Put thefe ingredients into an iron pan of fuch a fize that it 

 may be only half full ; mix them well together, and boil 

 them till all the moilture is evaporated, which may be known 

 by a pellicle being formed on the furface, or by the barrel 

 of a quill hurtling wheii thruft to' the bottom of the boiling 

 Tarnidi. Then take it from the fire and pour oft' the clear 

 liquid, taking care to keep back the thick part which ha» 

 depofited itfelf at the bottom. While boiling, it muft be 

 ftirred feveral times round, that the litharge may not fall to the 

 \)Ottom3 but you muft not ftir it coultauily, elfe fupertluous 



litharirtj 



