376 DESCRIPTION OF THE MUSEUM. 



The first class is that of earthy substances con- 

 taining an acid, the salts of former systems ; the 

 second class comprehends earthy substances, or 

 stones ; the third presents an assemblage of dif- 

 ferent inflammable substances ; and the fourth 

 comprises the metals. 



The cases which contain this collection are 

 numbered and divided into shelves. At the height 

 of the eye are placed the specimens specially 

 intended for the use of students ; they are ar- 

 ranged on smaller shelves, connected together 

 like steps, forming little stages. The specimens 

 follow uninterruptedly in the same case, begin- 

 ning from the lowest shelf ; so that in passing 

 from one case to another, the first specimen of 

 the one comes immediately after the last speci- 

 men of the upper shelf of the preceding. Above 

 and below the stages, on the shelves, are pieces 

 remarkable for their size ; they belong to those 

 species on the stages to \vhich they are connected. 

 They shew these same species in their various 

 associations with other mineral substances, and 

 recall the different localities in which ihcy have 

 been found. As these specimens are of various 

 sizes, and are not all of equal interest, it was 

 impossible to arrange them in the same systematic 

 order ; the larger pieces have therefore been 

 placed in the lower part of the cases, whilst 



