524 MINERALOGY. 



often decompose them, and they should as carefully be 

 secured from water, which would operate in a similar way ; 

 for the use of the INIineralogist, Messrs. Knight, of Forster- 

 Lane, London, hare formed Boxes of instruments necessary 

 to the practical Mineralogist. As no other instruction is neces- 

 sary in packing the generality of Mineral substances than 

 to avoid friction, the Boxes should be strong, and the joints 

 close, so as to exclude the air, and the insterstices between 

 the specimens should be carefully filled with some substance 

 that will effectually prevent attrition. As a branch of Mine- 

 ralogy, we shall just notice that most countries afford a 

 Tariety of fossil substances, which are highly interesting, and 

 merit the attention of the Traveller ; in chalky countries 

 numerous fossil remains of organized bodies are constantly 

 occurring, particularly the bones and teeth of Animals, as 

 also the shells of Crabs, Echinae, &c. &c. ; these should be 

 carefully packed in paper, and kept from the air : some 

 kinds are found in the fissures of Rocks, others compacted 

 in the solid substance of Rocks or Stones, many kinds abound 

 in stiflf Clays at great depths beneath the surface of the earth ; 

 some are occasionally found in the beds of Rivers, or in beds 

 that have long been dry ; as likewise among shingle on th« 

 sea beach. 



la making sketches illustrative of the Geology of any 

 country, the direction in which the veins or strata may rua 

 should be particularly observed, as whether they be vertical, 

 oblique, or horizontal, if the strata be entire or broken, 

 their distance from the surface, with the intervening strata, 

 where they can be observed from the base to the summit ; if 

 their station be on the shores of the ocean or inland, if tra- 



