in its Relations to Chysiology. 441 



&c. An experienced eye perceives, immediately, that this method has 

 not really been tested by analysis, which, moreover, would render 

 necessary various methods, according to the varying relative propor- 

 tions of the metals, and that it is fraught with more difficulties and 

 sources of error than the common method of separating with ammonia 

 and potass." 



Altogether disregarding the circumstance that Berzelius gives an 

 incorrect report of my method, this is not the first occasion on which 

 he has deserted his formerly so stoutly-defended principle of allowing 

 facts to speak and not opinions. I think it would have been better to 

 have made an experiment than to have expressed an opinion based, as 

 it is, upon an erroneous notion. Berzelius would then, probably, have 

 satisfied himself, and this with the aid of my method, that the separa- 

 tion of cobalt from nickel by means of ammonia and potass is very in- 

 complete and imperfect, since either the oxide of cobalt remains in 

 solution, or the precipitated oxide of nickel contains oxide of cobalt. 



I am, as is well-known, a teacher of chemistry in a university, and 

 annually instruct above one hundred students in the art of analy- 

 sing minerals, and, amongst others, in the separation of nickel from 

 cobalt. My method, which Berzelius thinks exists only on paper, is, 

 therefore, very often tried, and hitherto it has been found, invariably, 

 that no better method can replace it ; perhaps, because it depends upon 

 a more correct principle of separation than other methods. I can only 

 express my regret that Berzelius should have paid so little attention to 

 the experiments of Fresenius and of Haidlen relating to the application 

 of cyanide of potassium in chemical analysis, for these experiments 

 constitute the most valuable contribution which mineral analysis has 

 of late, received. 



Manufacture of Epsom Salts, 

 The note, page 310 in our last number, relative to the 

 process suggested in the paper of Lieut. Latter on the me- 

 thod of treating sulphurets of copper at Lyons, having attract- 

 ed the notice of Messrs. Bathgate and Co., it was intimated 

 to us, that sulphuric acid since the erection of their large 

 chamber, has become so cheap as to be had for little or no- 

 thing. Conceiving the circumstance to be favourable for 

 resuming the experiments in the manufacture of salts, re- 

 ferred to vol. 2, p. 244, we ascertained from Messrs. Bathgate 



