M. MeHg m fhe Discotny vf Usefu! Mingmh. BBi 



tigation in order to renew It in the opposite direction, or on 

 the opposite side of the mountain, perhaps with the same re- 

 sult. Perseverance like this is necessary, and no one will 

 think my advice exaggerated, who has sufficiently studied 

 in nature the repositories not only of useful minerals, hut also 

 of other minerals, which are sought for without exact investi- 

 gations and mining contrivances. We unexpectedly find a re- 

 currence of repositories of minerals, Avhich we have observed 

 at one point or in a district under certain circumstances, af- 

 ter miles of country have intervened, and after they have pro* 

 bably been forgotten, and we often detect their identity by 

 means of trifles ; for auxiliaries like those which are taken for 

 granted in the search of useful minerals, are not easily obtained 

 by the travelling geologist. ^Ye must, therefore, pursue the 

 investigation, at all events within the boundaries pointed out 

 b}- the nature and object of the search, uatil a perfectly well 

 grounded result has been obtained, even though such should 

 be unfavourable ; and this result can only be attained in the 

 manner which has been pointed out. 



We have previously spoken of a place to which our aim 

 must be more especially directed during the investigation of 

 the repository. That place is the one most conveniently si- 

 tuated, and the most suitable, and which allows of the ex- 

 posed repository being examined as to its being worthy of 

 mining operations. Thus, it does not follow that a repo- 

 sitory should be every where, or any where, of a description 

 to warrant these operations ; and the ascertaining generally 

 whether the repository is of sufficient importance, requires a 

 particular investigation and judgment, of which we shall speak, 

 in what is to follow. But it also does not follow, at least un- 

 conditionally, that a repository worthy of being mined can be 

 excavated with advantage at every point ; and hence we have 

 not only to distinguish both with sufficient exactness, but also 

 to search for and uncover those points which, if the repository 

 is sufficiently valuable at any part, are to be preferred in the 

 latter point of view. We should endeavour to uncm'er the repo- 

 sitory at such points, in order to submit them to more minute 

 examination. The commencement of actual mining excava- 

 tions requires a particular^ viz. a purely mining knowledg'e, 

 and in that reeiieot does not belong to om* jn-esent stibject ; 



