164 Scienirjic Intelligence. 



agencies, living and physical, concerned in modifying them, and 

 many fine plates illustrate the topics discussed. The paper closes 

 with observations on the action and reaction of man and the soil. 



8. Cambrian Fossils of New Brunswick. — Bulletin of the 

 Natural History Society of New Brunswick, No. X, St. John, 

 N. B., contains a paper on Protolenns, a new genus of Cambrian 

 Trilobites from the St. John group, by G. F. Matthew. The 

 same genus is described by Mr. Matthew and two species figured 

 in the Canadian Record of Science for October, 1892. 



9. Experiments in Physical Geology. — Professor Ed. Reyer of 

 Vienna has lately issued three interesting brochures upon subjects 

 in physical geology. They are entitled : Ursachen der Deform- 

 ationen und der Gebirgsbildung (pp. 40) ; Geologische und Geo- 

 graphische Experimente, Heft I, Deformation und Gebirgsbildung 

 (pp. 52) ; Heft II, Vulkanische und Massen-Emptionen (pp. 55, 

 Wm. Engelmann, Leipzig.) The first named is a general state- 

 ment of conclusions based on the experiments which are very 

 thoroughly illustrated in the last two. The subject is treated in 

 the form of a discussion of several hypotheses to explain mountain- 

 making. These are: I, Changes of substance as by oxidation, 

 hydration, solution, etc. ; II, Contraction of the earth ; III, Dif- 

 ferences of density; IV, Loading or as it is termed the " Onerar- 

 hypothesis;" V, Hypotheses based on heat; VI, Deformations 

 due to eruptions. The author's wide experience in many regions 

 of geological disturbance and of igneous activity enables him to 

 throw much light upon the subject treated. The numerous ex- 

 periments were made on small models, which were compressed in 

 the usual way with a screw. Materials of varying firmness were 

 employed, so as to represent both stiff and yielding strata. The 

 results of the successive steps in each experiment are liberally 

 illustrated, so that the application to the similar cases in nature 

 are obvious, almost without the verbal explanation. J. f. k. 



10. Brief notices of some recently described minerals. — Geikie- 

 lite and Baddeletite are two species described by Fletcher as 

 occurring in the form of pebbles in the gem washings near Rak- 

 wana, Ceylon. 



GeiJcielite shows two cleavages at right angles to each other, 

 one of them perfect. It has a splendent metallic luster and 

 bluish black color, though thin cleavage flakes have a purplish 

 red tint. The hardness is 6*5 and specific gravity 3*98. An 

 analysis shows it to be a magnesium titanate, MgTi0 3 correspond- 

 ing to perovskite, CaTi0 3 . 



Baddeleyite resembles columbite in general aspect and has a 

 specific gravity of 6*02 and hardness of 6*5 ; the crystallization 

 is probably monoclinic. In composition it is also highly interest- 

 ing, it consisting of zirconia, Zr0 2 , an oxide not before found 

 among minerals but whose existence in nature was to have been 

 anticipated. — Nature, Oct. 27, 1892. 



Brazilite is described by Hussak from the granular pyroxenic 

 rock called jacupirangite at the iron mine of Jacupiranga, Brazil. 



