burat's geologie appliquee. 133 



II. Geologie appliquee, par M. Am:edee Bukat, Professeur 

 d'Exploitation des Mines a l'Ecole centrale des Arts et Manu- 

 factures, &c. 1 vol. 8vo. pp. 504. Paris. * 



This treatise, by M. Burat, contains a large amount of useful in- 

 formation on subjects connected with mining, although it is chiefly 

 valuable in reference to the mineral resources and the mining ope- 

 rations of France. The author introduces his subject by a state- 

 ment of the relative importance of the various minerals in different 

 countries, and states that, with regard to France, although in the 

 eighteenth century there was a period of great activity, nothing was 

 then undertaken with a view to the future, so that as soon as the 

 stores existing near the surface were worked out, the competition 

 with other countries threw a check upon these operations, and a 

 large number, especially of the lead mines, were abandoned. 



The first part of the " Geologie Appliquee " relates to the geo- 

 logical position of the useful minerals, and commences with a general 

 view of the different geological formations. An arrangement is 

 adopted, previously suggested by Werner, which groups all rocks 

 that contain mineral produce into two classes, the first of which are 

 characterized by being found stratified, or massive, while the latter 

 occur only in veins, or are otherwise disseminated in comparatively 

 small quantities. 



This arrangement is convenient, especially in practical descrip- 

 tions, as very distinct methods of working are adopted in the two 

 cases. 



It is unnecessary to dwell on the notices given concerning the 

 sedimentary and igneous rocks ; but a very useful chapter is written 

 by M. Burat, defining the relative economic value of these and their 

 usual mineral produce, and mentioning those parts of France in 

 which they occur. A table is given also at p. 29. containing a sta- 

 tistical account of the results of quarry-work of all kinds, and the 

 nature and value of the produce in the different departments of 

 France, and to this are appended a number of notes, marking the 

 limits of supply in the more important cases. The date of the 

 table is probably 1840, and the total value of the supply is stated at 

 somewhat more than forty millions of francs (1,600,000/.). 



Continuing the description of the gites generaux, or instances of 

 entire strata possessing economic value, M. Burat, having alluded 

 to building-stones and other cases in which the rocks are quarried 

 at the surface, proceeds to the subject of coal and other combustible 

 minerals ; and in this the application of Geology to economic pur- 

 poses is ingeniously shown, and suggestions are given of great 

 practical utility. Among these is one derived from the trials for 



* This book appears without a date, an omission of some importance in a 

 work which professes to give accurate statistical tables on subjects constantly 

 changing. The editor obtained it in Paris in the autumn of 1843, and had 

 reason to believe that it was then recently published. 



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