me. 
II. Remarks on the Transition Rocks of Werner. By 
Tuomas AuLan, Esq. F.R.S. Edin.* 
Acrnovcn we have many writers on geological subjects, 
whose works are distinguished by ingenuity of doctrine, 
and novelty of opinion, and, among them, some who have 
made advances towards arrangement; it was reserved to 
the celebrated Werner, to introduce means, by which rocks 
might be described with some degree of precision, Man 
ingenious theories were invented, to account for their for- 
mation; but little or no attention was paid to the ac- 
guirement of an accurate knowledge, cither of their com- 
position, or their relative position in nature; although these 
certainly appear to be the bases, on which such speculative 
opinions ought to be founded. 
But while we acknowledge these obligations. to the Pro- 
fessor of Freyberg, we cannot extend our unqualified ap- 
robation to the systematic arrangement he has imtroduced. 
tt was not to be expected, that the labours of one indi- 
vidual, who, from peculiar circumstances, was confined 
within certain limits t, were sufficient to attain perfection; 
nor could it reasonably be supposed, that any district, how- 
ever extensive, should be so singularly favoured, as to con- 
tain all the variety of facts, that occur in other parts of the 
world, from which deductions are to be drawn, and eluci- 
dations afforded, investing phenomena with characters 
which they do not present elsewhere. 
An forming his arrangement, Werner may have exhausted 
the means he possessed; he, therefore, ought not to be re- 
proached; for although his conclusions are more general, 
than are warranted by the circumscribed field to which he 
was confined, yet he has formed a groundwork, on which 
the labours of future geologists may rear a system more 
capable of affording satisfaction. 
It is greatly to be wished, that arrangements of this kind 
were less dictated by theory. The pupils of the Wernerian 
, school have been peculiarly fettered, by an ideal necessity 
of supporting the principles of their master; but the blend- 
ing of theory with description, is an error common to all 
* From the Transactions of the Royal Society of Edinburgh.—I am de- 
sired by Mr. Allan to state, that the insertion of this paper in another 
Monthly Journal, before the regular publication of the Edinburgh Trans- 
actions. was without his concurrence or knowledge.—A. ‘Il’. 
+ In Werner’s Preface to his Theory of Veins, he states, that his limited 
fortune, and the nature of his present situation, prevented him from travels 
ling into more distant countries.-.-Anderson’s ‘L'ranslation, xxiii. 
speculative 
