804 Analyses of Booh. [April, 



many uses by our predecessors, who were ignorant that this mineral 

 consists entirely o( pure carlon, as it is by us, who are acquainted 

 with that face — a fact which must be admitted to be curious and 

 important ; but not to constitute every thing of any value with 

 respect to the mineralogy of the diamond. Gypsum was well known 

 by its properties, and was applied to all the purposes for which it is 

 used at present, before Margraaf and Lavoisier ascertained it to be 

 a compound of sulphuric acid and lime. A mineralogist may be 

 very well acquainted with the characters of gypsum, capable of dis- 

 tinguishing it from all other minerals, and aware of the different 

 uses to which it is applied, though he be ignorant of the consti- 

 tuents which enter into its composition. 



We must not, therefore, confine the science of mineralogy to the 

 mere knowledge of the constituents of minerals. It includes many 

 other particulars of great importance, and has frequently got the 

 start of cliemical analysis in its conclusions. Thus calcareous spar 

 and arragoniie were considered by mineralogists as two distinct 

 species, even when the most expert chemists were unable to discover 

 any difference in their composition. When chemical analysis shall 

 have arrived at a state of perfection, we may expect to find it agree 

 in every respect with the conclusions drawn from the external cha- 

 racters ; but in its present imperfect state, such discrepancies can- 

 not be avoided ; and when they do occur, it is but reasonable to 

 give the superiority to the deductions from the external characters, 

 as less likely to mislead us than an imperfect chemical analysis. 



The object of Berzelius in the present little work is to show that 

 all mineral species are really chemical compounds, composed of 

 ingredients combined in definite proportions, and capable of being 

 classified into orders, genera, and species, according to their com- 

 position, just as may be done with the salts. Though numerous 

 analyses of minerals exist, yet it must be confessed that these defi- 

 nite proportions, this chemical composition according to the atomic 

 theory, can be perceived only in a small number of individuals j 

 while the great body of tlie mineral kingdom seems to bid defiance 

 to the a[iplication of the laws of chemistry. But this discordance 

 Berzelius considers, and I believe with justice, as only apparent, 

 and not real. He ascribes it to three causes : 1. The inaccuracy of 

 experimenters. 2. The mechanical mixture of foreign bodies with 

 the chemical compounds, in consequence of the situation in which 

 they were when they became solid or crystallized. 3. The deposi- 

 tion of two different compounds in contact with each other, which 

 gives occasion to a form different from that of either of the com- 

 pounds. Thus arragoniie owes its form to the deposition of an atom 

 of carbonate of strontian in contact with carbonate of lime at the 

 time of its crystallization. 



The minerals which it has liitherto been impossible to bring 

 under the laws of chemical combination are the stones, composed 

 chiefly of silica, alumina, lime, and oxide of iron, united in 

 Viirious proponiuns. Professor Berzelius conceives that in these 



