L66 Scientific Intelligence. 



In experiments L-9 the heating was carried on in a covered 

 crucible over n bnnsen burner, and experiment lo in a fnrnace. 

 In experiment 8 the heating was conducted in a cnrrent of 

 hydrogen and in experiment !' in an atmosphere of carbon 

 dioxide. 



The best conditions seem to involve a moderate excess of 

 charcoal with about an hour's heating. 



May, 1911, 



SCIENTIFIC INTELLIGENCE. 



I. Geology and Mineralogy. 



i 



1. La GranodiorUa de Conception del Oro en el Estado de 

 Zacatecas, y sus Formaciones de Contacto ; por A. Bergeat. Bol. 

 del Inst. G-'eol. de Mexico, No. 27 ; 1910. 4°, pp. 109, 9 plates. — 

 After a general description of the region, with a brief account of 

 the stratified rocks, the author describes the principal mass of 

 granodiorite with petrographic details and chemical analyses. 

 After mention of schlieren and inclusions he then takes up the 

 subject of the contact metamorphism, both endomorphic and exo- 

 morphic. The former consists partly in a change of grain and 

 partly in the intense absorption of lime from neighboring lime- 

 stones, whereby an intermediate zone of garnet rock is produced. 

 In the latter the limestones are converted into marble, filled in 

 places with garnet, wollastonite, vesuvianite and other minerals. 

 In some places at the contact are deposits of pyrite and chalcopy- 

 rite, in others hematite and magnetite, with blende and tennant- 

 ite with quartz, which are referred to emanations from the 

 magma. These various features, with the mines, are described in 

 detail, the whole forming a valuable contribution to Mexican 

 geology, and to our knowledge of the occurrence of ore deposits. 



l. v. p. 



2. Fourteenth Annual Report of the Geological Commission 

 of the Cape of Good Hope for 1909. Pp. 116, vi. Caj)e Town, 

 1910. — This report is comprehensive in character and presents the 

 results obtained by the Director, A. W. Rogers, working in con- 

 junction with A. L. r>u Toit. The geology of Kenhardt, Prieska, 

 and Carnarvon, is fully described ; this is the region extending 

 from the Orange River to Upington and southward to near 

 Carnarvon. The most important part of the work has to do with 

 the old formations referred to under the so-called Kheis series 

 and the granitic rocks associated with them. Some new facts are 

 also given in regard to the bowlder beds of the Dwyka series, 

 and the Kimberlite pipes and dikes in Carnarvon and Victoria 

 West. 



