( 9S0 ) 
tho at firft there was fome difficulty to make it take fire 5 pre* 
chance fome other matter not unftuous being tnixt with it. 
And laftly, Since, being obferved with the Microfeope, its 
compofition (hews like that of Oyl or Lard,or the like unftu- 
ous matter, it is very likely from all thefe, that it is com- 
pofed of the Gum or juice of fome Refinous Herb or Tree, 
or of the fat of fome Animal, or Hogs Lard. And to make 
fomeguefs^ who knows but the Gall of fome creature 
may be mixt with it, to make it the more eafily receive a 
fmoothnefs and luftre, as Limners ufe to put Gall into their 
Water-colours, to make them run and fpread the better 5 
and that the mifchicf we find in touching and ufing it may 
proceed from hence. 
I verily believe, there is no Mercury, of what.fort fo- 
ever, in this Varnifh ^ not only becaufe it is very light (as 
was faid ) but befides, becaufe I have been very diligent 
in trying whether Gold would difcover any fign of Mer- 
cury, either in the body of it, or the fmoke, but could ne- 
ver find any 5 and moreover. Mercury produces very diffe- 
rent effefts in our Eodits, from thofe before related of 
this Varnilh. 
Befides, I have obferved that the Varnifh, mixt with 
Spirit-of Vitriol, or Juice of Limons or Vinegar, or Spirit 
of V/ine, makes no ebullition nor change of colour 5 but 
it readily changes colour, when taken out of the Veffel, it 
is expofed to the air, becoming at firft reddifti, and after- 
wards almoft quite black ; the outward skin of it, which 
is next to the air, becoming yery hard and black : This 
Skin is very thin, under v/hich the reft of the Varnifti re- 
mains foft and fluid, of the colour and confiftenceof Ho- 
ney - and as often as you take off this outward black hard 
skin, there will another be formed immediately like the 
former, and this as often as you pleafe to repeat the expe^ 
nment. So that the whole fubftance of the Varnifti will 
in time be changed into thele hard and black skins. 
Fi- 
