476 Intelligence and Miscellaneous Articles. 



The results obtained lead to consequences of which the following 

 are the principal : — 



1. With an electro-magnet, of which the iron was 7 centimetres 

 in diameter (instead of 1 1 centimetres, as in the previous experi- 

 ments), the repulsive action exerted upon bismuth, water, &c. does 

 not vary in proportion to the square of the intensity of the current 

 which circulates round the electro-magnet, except just at the inten- 

 sity corresponding with 15 to 20 Bunsen's couples ; with a larger 

 number of couples rising to 60, the relation between the action mea- 

 sured by the balance and the square of the intensity diminishes in 

 proportion as this intensity becomes greater. The actions exerted 

 upon different substances at different magnetic intensities lead, with 

 some, to a specific magnetism, which varies with the magnetic in- 

 tensity. 



2. Between the limits of intensity of currents of from 10 to 60 

 elements, the specific magnetism of oxygen compared with that of 

 water does not vary sensibly -^\X\ of its value. It is in the direct 

 ratio of the density of the gas. 



3. At 32° F., and a pressure of O m- 76, the specific magnetism of 

 oxygen, compared with that of water, is on the average + 0'1823. 



4. The action exercised by atmospheric air is measured by ^pg^dths 

 of the action of oxygen under the same circumstances of temperature 

 and pressure. 



5. The following numbers have been obtained to represent the 

 specific magnetism by volume of some solid and gaseous substances 

 at 32° F. and a pressure of O m- 76, the intensity of the current being 

 comprised between 30 and 60 Bunsen's couples. 



Water 



xygen 



Deutoxide of nitrogen 



Air 



Chlorine 1 according 



Amrnoniacal gas >to aqueous 

 Sulphurous acid J solutions. 



Specific 

 magnet- 

 isms. 



-1 



+01823 

 +00498 

 +00383 

 -00046 

 -00020 

 -0-0005 



Water 



Copper (galvanic deposit).. 



Copper (pure) 



Silver (pure) 



Nativegold(massweighing "I 



4813-5) J 



Gold (pure) 



Bismuth 



Specific 

 magnet- 

 isms. 



-1 



-1-41 



-1-68 

 -2-32 



-2-41 



-3-47 

 -22-67 



6. This method of experiment, which has enabled me to check 

 that which I employed in my first investigations, but which never- 

 theless is less delicate than the latter, did not allow me to determine 

 the diminution of the magnetic attraction which oxygen seems to 

 undergo when its temperature is raised (the density remaining 

 equal)*. — Comptes Rendus, April 16, 1854, p. 910. 



* From the abstract of M. E. Becquerel's researches here presented to 

 us, the reader would be led to infer two things : — first, that the differen- 

 tial method of experiment is M. E. Becquerel's method ; and secondly, that 

 the discovery of the magnetic properties of oxygen is M. E. Becquerel's 

 discovery. Both of these inferences would be contrary to fact. Nearly 

 four years before M. E. Becquerel made use of the differential method, it 

 was applied with success by Mr. Faraday (see Experimental Researches, 



