434 



Miscellaneous Intelligence. 



nttic intensities made witliin doors are uncertain, — Zach's Cor- 

 respondence. 



19. Intcnsiti/ of the Magnetic Force in different parts of the 

 World. — The following table is the result of Professor Hanstein's 

 laborious observations. 



20. Magnetism affected bi/ Earthquakes. — M. Arago has trans- 

 mitted to the French Academy of Sciences, an account of an 

 observation he had made, which proves that the recent earthquake, 

 the shocks of which were felt at Lyons and its neighbourhood, 

 also extended its action to Paris. M. Arago has an observatory 

 at Paris, for the purpose of observing the variations of the mag- 

 netic needle. On the 19'h February, the needle remained per- 

 fectly steady until half-past eight o'clock ; at a quarter before 

 nine, it became agitated in a very extraordinary manner, with an 

 oscillatory motion in the direction of its length. On observing 

 this truly singular phenomenon, M. Arago was of opinion that it 

 was occasioned by an earthquake. 



At the same day and hour, M. Biot remarked an oscillating 

 movement produced by the same earthquake, at his own residence 

 in the College de France. 



iii. Natural Histoky. 



^ 1. Mineralogy, Geology, Meteorology. 



1. Analysis of Yellow Copper Ore, by Mr. Phillips. — Mr. Phil- 

 lips has lately analyzed the different varieties of yellow copper 

 ore, and has arrived at the conclusion that they are all of similar 

 composition. His process was, after pulverizing the ore, to heat 

 it in nitro-muriatic acid until the sulphur was acidified, filter, pre- 

 cipitate by nitrate of barytes, and collect the sulphate ; then se- 

 parating the excess of barytes from the solution by sulphate of 



