in the Native Black Oxide of Manganese, 259 



muriates which the oxide used might, in the first instance, have 

 contained, '* I washed it every day, for three weeks successively, 

 using sometimes hot and sometimes cold water : at the end of 

 that time J I tested the water, which was then decanted from the 

 washed manganese, by the nitrate of silver, but without finding 

 the slightest appearance of precipitated chloride. I, then poured 

 upon the manganese four times its weight of dilute sulphuric 

 acid ; allowed the mixture to stand for about four lueeks, occa- 

 sionally agitating it, and at the end of that time, found, when 

 the dilute acid, now of a deep crimson colour, was removed 

 from the subsident manganese, and the latter agitated, that the 

 most decisive evidence of the presence of chlorine was exhibited 

 ia the vapour evolved from it." I stated further, that I had 

 *' carefully preserved this particular mixture, and that after 

 a lapse of more than twelve months, the residuary manganese, 

 when the supernatant acid was removed, continued to evolve 

 chlorine." 



In this experiment my object was effectually to purify the 

 manganese used from any soluble muriate which might by 

 possibility have been mixed with it : I did not, however, test 

 the water first used in washing it, but merely that which was 

 la^t removed from it. 



Mr. Phillips proceeds to observe that he had prepared some 

 observations, and at considerable length, to prove that the 

 author of the above paper has been completely misled by "forced 

 analogies" and '^erroneous experiments ;" but that it afterwards 

 occurred to him, that it would be better to show, in a few words, 

 the real source of the chlorine in question, the evolution of 

 which from peroxide of manganese he had noticed some time 

 previous to the publication of my papers. That with this view 

 he had procured various specimens of the peroxide of manga- 

 nese, (one of them in the crystallized state,) which were reduced 

 to powder, and on the addition of sulphuric acid, chlorine was 

 evolved from each. That he then washed separate portions of 

 them with distilled water, and on the addition of nitrate of 

 silver to the washings, chloride of silver was immediately preci- 

 pitated : sulphuric acid being poured upon the washed peroxide, 

 no chlorine whatever was evolved. That he further added 

 sulphuric acid to an unwashed portion, and to one which had 



