In No. V. of this Magazine (page 149) there appeared a paper on "Some new Minerals in the Collection of the Hunterian Museum, Glasgow," in which I gave a description and analysis of a new Sulphide of Lead, Manganese, Iron, and Zinc, to which I gave the name of "Youngite." In a note to his abstract of the above paper for the Journal of the Chemical Society of January, 1878, Dr. Burghardt, expressed an opinion that the "Youngite" was only a mixture of Galena, Blende, Alabandite (Mn S), and Iron Pyrites; and consequently had no claim to be called a new mineral. Although my analyses agreed closely, and coincided with such a probable formula that there was little reason to doubt their accuracy, I am glad to be able to place the matter beyond dispute.