Metalliferous Beds. 35 



which can be of use also in the latter case. I allude to the 

 arrangement of certain ores and mineral substances belonging 

 to beds in repositories of the nature above described. 



It is easy to be remarked that all ores which occur in beds 

 are not associated with one another, and that they are not in- 

 discriminately accompanied by all the substances forming these" 

 beds. Moreover, we find that beds of a certain composition, 

 namely, such as contain certain ores and certain mineral sub- 

 stances, are as it were united to certain mineral masses, and do 

 not present themselves in others. This sometimes goes to such 

 a length in slate-rocks, that we only find such beds in those 

 places or regions which are composed of particular varieties of 

 this or that slate. Hence has arisen the idea of bed-formations 

 (Lagerformationern), which, although it cannot be referred to fixed 

 and certain characters, and generally, therefore, cannotbe spoken 

 of definitely, yet in the search for such repositories, can afford 

 useful assistance. Hence, in districts where several of these 

 repositories are known, it is of consequence in this occupation 

 to study as accurately as possible what may be the formations 

 of these repositories, and the phenomena of their arrangement, 

 inasmuch as experience has taught us that when {he general, and 

 hence essential, features are properly understood, a great con- 

 stancy is found to exist, which leads not only to the discovery, 

 but also to the determination, of the mining value of such 

 a bed, although, as already remarked, it cannot be reduced 

 to universally applicable characters or distinct rules, and must 

 be left to the study of those to whom is intrusted the import- 

 ant duty of searching for repositories of useful minerals, and 

 who really have this object at heart. 



Bed-depots and Bed-districts— "Whew metalliferous beds of 

 any kind whatever occur in a mountain district, they generally 

 do not present themselves singly, but several lie over and near 

 one another at indeterminate distances. Such a district is 

 generally properly termed a bed-depot {Lager-depot). It is at 

 the same time to be remarked, that beds of a certain forma- 

 tion do not exclude those which belong to a different forma- 

 tion, and that all taken together constitute what is denomi- 

 nated a bed-district {Lagerretiere). The ideas included under 

 the terms bed-depota and bed-districts, include in their details 



