B$ W. Sfufgeon, Esq., on the 



tuents. Ill the best kind of German silver (constituted of 

 copper eight parts, nickel six, aiid zinc three), a slight mag- 

 netic action has been detected, but in the inferior kinds of 

 German silver, ini(S which only about three parts of nickel 

 enter, I have not detected any magnetic action whatever. 

 Hence the magnetism of that portion of nickel is obviously 

 neutralised in that particular alloy. 



43. The metallic salts that I have examined, are some of 

 those most frequent in common use. The salts of iron were 

 the sulphate, the yellow and the red ferrocyanuret of potas- 

 sium, also Prussian blue. These, with the exception of the 

 yellow prussiate, are magnetic ; the sulphate of iron in the 

 highest degree of any of them. It is somewhat remarkable, 

 that the two kinds of prussiate of potash, where the propor- 

 tions of iron are so nearly alike (yellow 15 per cent., red 16 

 per cent.), should display such a material difference in their 

 magnetic characters ; and it is still more singular that 

 Prussian blue, which contains more than 45 per cent, of iron, 

 is less magnetic than the red prussiate of potash. The sul- 

 phate contains about 33 per cent, of iron, and is the most 

 magnetic of the whole. 



44. Pure sulphate of copper shews no magnetic action, but 

 that of commerce is highly magnetic, being, as I have ascer- 

 tained, adulterated with sulphate of iron. Hence, the mag- 

 net would be a good and speedy test for the quality of the 

 commercial salt. 



45. The following salts appear to be perfectly neutral to 

 magnetic forces : — Common salt, saltpetre, borax, sulphate 

 of magnesia, sulphate of soda, sulphate of potash, carbonate 

 of potash, and carbonate of soda. 



46. Thus far I have attempted to contribute to the list of 

 facts previously known, and to correct some errors which, 

 probably on account of the inefficient modes of investigation, 

 have crept into this particular branch of science. It is pos- 

 sible also, I think, that some of the facts which have now 

 been pointed out, may be an inducement to employ the mag- 

 net more extensively than hitherto in the laboratory of the 

 chemist. 



