[ 3*1 ] 
relation thefe bodies Hand in to each -other, and 
thereby furnifh himfelf with materials for ertablini- 
ing a Mineral Syftem, founded on fuch principles as 
Nature herfelf has laid down in them ; and this in 
his own ftudy, without being forced to have re- 
courfe to great laboratories, crucibles, furnaces, 
See, which is attended with a great deal of trouble, 
and is the reafon why fo few can have an op- 
portunity of gratifying their delire of knowledge 
in this part of natural hiftory. I do not pretend 
to fay, that the Pocket-Laboratory here deferibed, 
is in every refpecl as perfect as it is capable of 
being made : and I have In the foregoing pages 
indicated fome inllances where it is not fufficient ; 
yet thofe inllances are very few. Befides, the 
Ihort time fince it has been invented, and the few 
perfons that have known how to make ufe of it, 
area fufheient apology for its not being brought to 
the utmoft degree of perfection. It is to be hoped, 
that the more general its ufe be made, the more 
. and fooner will fuch imperfections be removed, and 
fuch wants filled up, as will be found necelTary and 
convenient. I ihail now add fome hints towards 
thefe improvements, leaving to the judicious prac- 
dtioner the manner of completing them. 
SECT. LIIL 
A greater number of fluxes might, perhaps, be 
found out, whofe effeCts on mineral bodies might 
be different from thefe already in ufe, whereby 
more diftinfl characters of thofe miineral bodies 
might be difeovered,' which now either flievv am- 
biguous ones, or which are almofl impoifible to 
try exactly with the Blow-pipe. Inflead of the fal 
fod^^ fome other falts might be found out, more 
Bt for thefe experiments. But it is very ncceffary 
X 4 not 
