Astronomy. 257 



cleavage. They were all of small size, those mentioned being 

 respectively '5x3, 1 X2*5 and - 5xl'5 mm. 



The pyramid -f was observed by Rinne, Greim and Cundall, 

 and the pyramid •§- by Levy, Greim, Cundall and Hutchinson.* 



The following are the angles measured and calculated ; the 

 former did not vary more than 20' in each case. 



ADgie Angle 



measured. calculated. 



J A f 54° 21' 53° 9' 50"f 



I ^ i 43 47 42 5 



\-2 /v |-2 38 12 36 42 



Mineralogical Laboratory, Columbia College. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Law and Theory in Chemistry • a Companion book for 

 Students. By Douglas Carnegie, M.A. 12mo, pp. viii, 222. 

 London, 1894 (Longmans, Green & Co.). — This little book con- 

 tains the substance of a summer school course of eight lectures 

 delivered before an audience of school teachers of elementary 

 chemistry at Colorado College, Colorado Springs. As its title in- 

 dicates it is not intended as a text-book, but is offered as a resume 

 of the more important fundamental principles of chemistry which 

 are less fully considered in ordinary manuals. The subjects 

 treated are Alchemy, the Phlogistic Theory, Chemical Classifica- 

 tion, the Atomic Theory, the Classification of Compounds, Iso- 

 merism and Molecular Architecture, and Chemical Equilibrium. 

 These chapters are clearly and accurately written and the book 

 will be a valuable aid to the earnest student. It is to be regretted 

 that it is not provided with an index. g. p. b. 



II. Astronomy. 



1. A Treatise on Astronomical Spectroscopy : being a Transla- 

 tion of "Die Spectralanalyse der Gestirne," by Prolessor Dr. J. 

 Scheiner, Assistant at the Royal Astrophysical Observatory at 

 Potsdam. Translated, revised and enlarged, with the coopera- 

 tion of the author, by Edwin Brant Frost, M.A., Assistant 

 Prof, of Astronomy in Dartmouth College. 8°, pp. xiii, 482. Figs. 

 81 ; PI. 2. Ginn & Co., Boston and London, 1894. — The novelty 



* Previously cited. 



f These values are based on Rinne's calculations. See Dana, Syst. of Min., 

 1892, p. 208. 



