2 6 Mr. woulfe’s Experiments on 
Saxon jafper, called ribbon agate, as alfo a red one, which 
was given me as coming from Johngeorgenftadt. From 
thofe I obtained very good allum, but can give no account 
of the particulars, -having loft the paper which contained 
the refult of my experiments. 
Yellow pitch Jlone , and wood like dale , petrified with pitch 
ftone , both from Hungary. 
The refult of my experiments on thefe fubftances was 
fet down on the lame paper with that of the jafpers 
which was loft; but I recoiled! to have only obtained a 
fmall portion of allum, and for that purpofe was obliged, 
before I obtained the allum well cryftallized, to wafh 
away the excefs of acid with rectified fpirit of wine. 
Yin fpar of the Germans, commonly called white tin ore. 
It has a fparry appearance ; but by its lamellated tex- 
ture and great fpecific gravity, which is equal to that of 
tin grains, is ealily known. This is fuppofed by feveral 
to be rich in tin; but the Saxon mineralogifts aftert, that 
it contains none. The only experiment I made with it 
was to digeft it in a powdered ftate with acids, by which 
means it acquires a rich yellow colour, like turbith mi- 
neral ; 
7 
