Q^ SCIENTIFIC NEWS. 



SCIENTIFIC NEWS, fcta 



Notice refpecling the Difcovery and Situation of chromated Iron 



in France. 



Chromate of ^~ / « Pontier has already found, three years ago, in the lower 

 "on. Alps, fbme fragments of chromated iron, out of its place ; 



but circumftances and the war prevented him from difcovering 

 the true pofition of this new and curious mineral in the earth. 

 He, however, at laft found it in its natural place in a quarry 

 near Gaffin, in the road to Cavalaire. 



This metal is mixed with a green ferpentine rock, which 

 probably owes its colour to the chrome, according to C. Pon- 

 tier's opinion. It fometimes forms maffes of five folid deci- 

 meters each. — Bulletin des Sc. No 57. 



BOOKS OF SCIENCE, 

 A Treatife on Aftronomy, in which the Elements of the Science are 

 deduced in a natural order from the Appearances of the Heavens 

 to an Ohferver on the Earth ; demonftrated on Mathematical 

 Principles; and explained by an Application to the various 

 Phenomena, By Olinthus Gregory, Teacher <rf Ma- 

 thematics, Cambridge. Octavo, 522, very full Pages, with 

 nine Copper Plates, exclufive of tlie Preface, Table of Contents 

 and Index, Kearfley, London. 



XT muft be admitted that we have few works in our lan- 

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 treatife with the interefting difcoveries of later times. 



His order confifts in an inveftigation of the figure and di- 

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 the fixed flars; parallax, refraclion, equation of time; fyf- 

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 of apparent motions; law of the planetary revolutions ; real 

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 iits, cometary phenomena; aberration of light; elements of 

 computation, tables, &c. Sec. L. L. 



