Mr. Greville on the 
of his Imperial Majesty, obtained his enrollment among the 
bellows of the Royal Society. He connected the intrinsic 
and extrinsic characters of minerals, in the Index Foss ilium, 
which he published in 1772. In Sweden, Bergman’s treatise on 
the forms of crystals, published in the Upsal Transactions, in 
1773, was a more authoritative recommendation to the inves- 
tigation of the principles of crystallization ; and it can be of 
little importance for me to add, that since I have possessed 
the collection of Baron Born, in 1773, I have had every con- 
firmation of the same opinion. The progress of chemistry and 
of crystallography, applied to mineralogy, has rendered the exa- 
mination of strata, and of mines, a source of amusement as 
well as instruction ; and the arrangement of interesting facts, 
in the chemistry and mechanism of nature, suits my occasional 
researches in geology, which, from variety of avocations and cir- 
cumstances, have been very much interrupted. My acknowledg- 
ment of obligation to the learned who have made this progress 
in science, is the best recommendation I can give to others to 
examine their works. Those whose talents and time are devoted 
to the investigation of every mineral substance, can have no 
respite to their labour ; minerals, in every state of their forma- 
tion, perfection, and decomposition, as they occur in mines, 
must have their qualities immediately ascertained, and be re- 
served for profit, or thrown away on the heap. The practical 
miner could not, 'without external characters, make any progress. 
The valuable minerals are soon pointed out by assay, and their 
appearance remembered. The accuracy of selection depended, 
in all pe iods, much on the experience of the miners. It re- 
mained for. Mr. Werner to give the utmost degree of accu- 
racy which irregular external characters can acquire, by fixing 
