viii DEDICATION. 
Figures, we muft recur to that AN 
mighty Wifdom aad Power which 
planned out the Syftem of Nature, 
directs the Courfes of the Heavens, 
and governs the whole Univerfe. 
The Experiments here defended, 
and which the Reader is inftrudted to 
make, mull I think generally enter¬ 
tain ; but merely to entertain, is, 
I hope, the leaft of their Worth. 
They may poffibly lead to the 
Knowledge of what paffes in the 
Formation of Gems, and the moll 
beautiful mineral Productions: And 
as every new Difcovery is an Encou¬ 
ragement to farther Difquifition, the 
Hints here given, may perhaps fet abler 
Heads at Work to improve Art on the 
Principles of Nature. Examinations 
by the Microfcope, in the Manner 
ht re direded, may likewife be em¬ 
ployed to afcertain the Truth and 
Purity 
