[ 354 ] 



LXVIII. Notices respecting New PublicatioBi and ike 

 Fine Arts. 



A Practical Essay on the Aiiali/.sis of Minerals, excmplifi/- 

 ing the i-est Methods of anahjnng Ores, Earths, Stones, 

 inffainvmhle Fossils, and Mineral Sidstaiices in general. 

 By Frederic Accum. l2mo. 



JyiR. Accum, to whom the public are tinder obligations 

 for a useful work of which we lately took some notice, 

 namely, A System of Theoretical and Practical Chemistry^ 

 has broaght I'orwarcl the present essay, as he informs us m 

 his preface, bv the express desire of a number of gentlemen. 

 to -whom he delivered a private course of lectures on prac- 

 tical chemistry. We have no doubt but it will meet with 

 a favourable reception, as it presents much useful informa- 

 tion on the subjects which it embraces. The following ex- 

 tract will ctmvey some idea of the nature of the work ; 



General Analysis of Earths and Stones. 



In the preceding pages we have considered earths and 

 stones solely with a view to discover their principal preva- 

 lent component parts, in order to determine therefrom the 

 genus to which the mineral belongs : we shall now enlarge 

 upon this subject more fuliv, by pointing out some general 

 observations, which may serve as a guide for separating all 

 the different earths that may exist in a mineral submitted 

 to our examination. In the analysis of earthy substances, 

 or stones, we must first attend to their solubility or insolu- 

 bility in acids ; and with that view we divide them into two 

 classes, namely, earths and stones, which effervesce with, 

 and are cither totally or nearly soluble in, nitric acid, di- 

 luted with five or six times its weight of water ; and such 

 as are not soluble in that acid. Suppose, therefore, that 

 the stone to be ejwimined consisted of silcx, aiumme, mag- 

 nesia, lime, sfrontia, and baryt€s. 



The method of separating these different earths will be- 

 came obvious from the following considerations : 



Process I. Reduce a quantity of the miTieral to powder, 

 *?id try tt'hctircr it effervesces with nitric or muriatic acid 

 •rfiltitcd in the abo\'e proportions ; if so, let a determinate 

 tjuantity be put into a tubulated retort of as little capacity 

 as possible, immerse the neck of it under a cylinder fdled 

 with water, and plac^^d in the pneumatic apparatus. 



If. Let a qi:amitv Wi mdtiatic acid be put at once through 

 3 ' the 



