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 _last_ 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 manganese, (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 precipitated: 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 [p260] been washed, and referred both to a _bystander_, who immediately detected the odour of chlorine in the former, but not in the latter. He then proceeds to show that the specimens of manganese which he had made the subject of this experiment contained a portion of lime, and he infers that the black oxide of manganese consequently contains muriate of lime.