

■ 



Experiments on Diamagnetism. 233 



Example 2.— Raise 10 to the 4th power. 



HereQ=10. declogQ=0. M=4. N=l. D=0. 

 4xl-(4x0 = 0)=--4or+4. =logofR. 



Hence R = 10000. 



Example 3.— Required the cube root of 0000111. 



Here dec log Q = -0457141. M = £. N=2. D = 6. 

 *x2-0457141-£x6= - 24-68 19047= log R. 



Hence the cube root of 00001 11 is 0-048073. 



Branch Mint, New Orleans, October 9, 1848. 



RT - XXII. — Abstract of a Series of Experiments on Diamag- 

 netism, ; by H. C. (Eksted of Copenhagen.* 



At the session of the Royal Society of Science at Copenhagen 

 on the 30th of June, (1848,) I presented the results of researches 

 which I had made in diamagnetism, and I gave a report of the 

 same in the Comptes Rendus of the Society. In the recess of 

 this Society I have continued my researches and obtained many 

 new results. As the memoir will not appear in the Society's 

 Transactions in many months, I have decided to give an abstract 

 oi my results which can be commuuicated to my foreign friends. 

 My researches relate to the celebrated discoveries of Dr. Fara- 

 way, and to the developments which these have received from the 

 German philosophers. 



Dr. Faraday encountered in his experiments with his great 

 electro-magnet, a class of bodies which are repulsed by the two 

 Poles of the magnet. This repulsion had been for a long time 

 well known in the case of two or three substances, but the re- 

 searches of the illustrious English philosopher have given to this 

 tact a generality and an importance which has rendered it the 

 object of attraction by all men of science. M. A. Brugmanns 

 had as early as 1778 noticed that bismuth was repelled by the 

 wo poles of the magnet. M. Becquerel (the father) observed 

 jtos repulsion anew, as relates to bismuth and antimony. Dr. 

 Faraday found that his great electro-magnet produced this repul- 

 s 'on upon almost all bodies which it did not attract. He dis- 

 covered also that bodies having unequal dimensions of length and 

 breadth, when thus repelled under the influence of an electro- 

 ma gnet, took a position perpendicular to that which an attrac- 

 tive body would take under the same circumstances. Tins is 



property 



periments 



ll Pon the lateral deviation in the descent of bodies which fall to the 



* Translated for this Journal from the Ann. de Ch. et de Phys., Dec, 1848 

 Skco.vd Series, Vol. VII, No. 20.— March, 1849- 30 





