On forming Collections of Geological Specimens. 269 
a constant supply, though not to the surface. I was induced to 
communicate these particulars to you, in the hope that some of 
your intelligent readers resident in that vicinity, or others that 
have visited it, may be competent to furnish more correct or 
further information on this subject. 
Iam, sir, 
Your most obedient servant, and constant reader, 
Wakefield, Sept. 10, 1817. W.S. 
XLV. On forming Collections of Geological Specimens; and 
respecting those of Mr. Smiru in the British Museum. 
To Mr. Tilloch. 
Sir, — ip cannot fail to be a source of pleasure to every one 
to witness the progress of discovery, particularly in those sciences 
which are of real use to mankind: and the more so, when the 
nature of the science is such, that there are few men of observa- 
tion who cannot contribute their mite towards its progress. 
Accordingly, we find that most of the useful sciences have at 
one time or another become objects of general attention, occa- 
sioned either by some fortunate discovery, or happy simplifica- 
tion of an apparently difficult branch of study. We are glad to 
find that geology, among the rest, is now beginning to share the 
attention of men of science, being well aware that its improve- 
ment will be the natural consequence. 
One great step towards this improvement, will be the forming 
of collections of specimens, on such principles as are best adapted 
to the purpose of identifying the superficial strata of the earth; 
and of elucidating the nature of their formation, and of the 
gradual changes which have taken place ou the surface of this 
planet. 
It cannot, however, be expected that the relative position or 
identity of a stratum is to be determined, with certainty, from 
any single character ; therefore it is obvious that a geological 
collection of specimens must differ materially from a collection 
of minerals. For the mineralogist, a simple specimen of each 
mineral substance is sufficient—but a fossil shell, petrifaction, or 
mineral is useless to the geologist, unless it be accompanied with 
a proper description of the stratum, and of the exact place from 
whence it was obtained: hence it is necessary that a descriptive 
catalogue should always accompany a collection of geological 
specimens. 
Mineralogy is an art that becomes more curious than useful, 
unless it be connected with geology or chemistry; but its useful- 
less 
