508 Sir G. C. Haiigliton on the Common Nature of 



Cobalt with M 90°; T foiled. 



Brass with M 90= ; I 90°, not easy; P. G. 90° f. ; PI. 90°; 



T 90° X ; L 90°, f. very easy and firm ; B. 90°, f. very 



easy, firm. 

 German silver with M. A.; P. G. 90°, f.; L 90°, f. very easy 



and firm ; Cop, 90°, f. most easy ; B 90°, f. strong ; GI. 



90°, f. very strong. 

 Bell-metal with M 90° ; P. G. 90°, f. ; T 90°, junction easy 



after the use of the magnetic needle ; L 90°, f". easy ; Cop. 



90^ f. firm; B 90% f. very firm; Germ. S. 90°; Gl. 90°, 



f. easy. 

 Arsenic with M 15°; I 34°; P. G. 19°; S failed; P 31.°; 



PI. 0°; Cad. 90° + ; T failed; L 90° ; Z 28°; Cop. 57°; 



B failed; Germ. S. failed; Ars. 65°; Gl. 52°. 

 Plumbago with M failed; I failed ; PI. failed. 



In this and the following classes, the results already ob- 

 tained with the magnetic needle are again repeated for the 

 sake of affording an easy means of comparison. The iron 

 needle was of soft iron wire, and on bringing it near a delicate 

 magnetic needle it caused no repulsion, but attracted the N. 

 and S. poles ; I therefore believe that if it had any magnetism 

 it did not influence the results, and if so it would have had a 

 tendency rather to diminish than to raise the measurements, 

 for often, as in the case of palladium, platinum, bismuth and 

 arsenic, iron has an advantage over the magnetic needle, 

 though, as may be observed with regard to antimony and 

 chromium, it often falls considerably behind it. Iron in its 

 normal state, that is free from adventitious magnetism, dis- 

 covers less affinity for other bodies, and even for itself, than 

 gold, cadmium, tin, copper, and some other metals. "When 

 it was made to attach itself to a bit of its own wire, the con- 

 nexion was broken with as much facility as was exhibited by 

 most of the metals. This result will be scarcely anticipated, 

 and is a further proof that it was devoid of free magnetism. 

 The polarity that iron exhibits is due entirely to extraneous 

 causes, and as my opinions have been long made up upon the 

 subject, I hope before long to make them known, and to show 

 that it depends upon causes of the simplest kind, if that ex- 

 pression may be applied to phagnomena in which so mysterious 

 an agency as affinity is concerned. Manganese exhibited only 

 an attraction of 10° for tin, and none for platinum. Chromium 

 had likewise no attraction for tin, and indicated only 19° for 

 gold, while for platinum it had an attraction of 90°, yet both 

 chromium and platinum are magnetic metals according to 

 Dr. Faraday's experiments, and gold diamagnetic. But all 



