736 PLUOKER ON THE DETERMINATION OF THE 



32. In saline solutions the original magnetism of the peroxide 

 is not enfeebled by the addition of acids to the latter. 



In the case of its combination -svith nitric acid, not the slightest 

 alteration occurred provided it was added to that peroxide from 

 which it had been prepared. The numbers representing the 

 magnetism in each case are 287 and 286. However, as the 

 latter number, in conformity with the previous investigations 

 (28.), is probably too great, the magnetism of the peroxide has 

 probably increased by the addition of the nitric acid. 



The magnetism of the pei'oxide, when in combination with 

 sulphuric acid, is greater than when in combination with nitric 

 acid, and more considerable w-hen in combination with hydro- 

 chloric acid than with sulphuric acid. The proportion (in the 

 solutions) is 



287 : 332 : 516. 



33. According to the tabular sketch given in paragraph 23, 

 the magnetism of green vitriol increases, when it is dissolved in 

 water, in the proportion of 



78 : 126. 

 The same likewise appears to be the case with the anhydrous sul- 

 phate of the peroxide of iron. In this casewe obtain the proportion 



111 : 133. 

 The magnetism of the dry salt is calculated from a previously 

 instituted compai'ison with the hydrate, with which it had been 

 simultaneously prepared (that detailed in the general sketch). 

 (See the table in paragraph 20.) 



34. In the case of nickel, the 21st paragraph proves the per- 

 fectly unexpected relation, that the hydrated protoxide is much 

 more powerfidly magnetic than the protoxide itself, the water 

 of hydration added to it increasing the magnetism about fourfold. 



The acid added to the oxide, in a solution of the nitrate and 

 hydrochlorate of nickel, as in the case of iron, also augments its 

 magnetism, and the hydrochloric acid more (although not to the 

 same extent as wdth iron) than nitric acid. 



35. Manganese exhibits a remarkable analogy to iron. I shall 

 not venture, in the case of either metal, to decide whether the 

 hydrated oxide as with nickel, is more powerfully magnetic 

 than the mere oxide. But a correspondence with iron consists 

 in the protoper oxide, which in the case of manganese is pro- 

 duced by heating the hydrated oxide to redness, being consider- 

 ably more magnetic than the hydrate, and probably also than the 

 oxide. 



