The charge is mixed, with addition of water, in a suitable pug-mill. The mass is then, while still wet, broken up into pieces 50 mm. (2 in.) in diameter, which are then allowed to dry on a floor in contact with air; in doing so they set hard, owing to the rehydration of the gypsum. As in the case of the Savelsberg process, the converters are heated with a small quantity of coal, are filled with the material prepared in the manner above described, and the charge is blown, regulating the blast in such manner that, after the moisture present has been dissipated, a gas of about 10 per cent. SO₂ content is produced, which is worked up for sulphuric acid in a system of lead chambers. The reactions are in this case the same as in the Savelsberg process, for here also calcium sulphate is formed transitorily, which, like other sulphates, reacts partly with sulphides, partly with silica. Where gypsum is available and cheap, the Carmichael-Bradford process must be given preference; in all other cases unquestionably the Savelsberg process is superior, owing to its great simplicity. LIME-ROASTING OF GALENA BY W. MAYNARD HUTCHINGS (_October 21, 1905_) Much interest attaches to the paper by Professor Borchers, recently presented in the _Engineering and Mining Journal_ (Sept. 2, 1905) on “New Methods of Desulphurizing Galena,” together with an editorial on “Lime-Roasting of Galena”; it is a curious coincidence that the same issue contained also an article on the “Newer Treatment of Broken Hill Sulphides,” in which is shown the importance of the new methods as a contribution to actual practice. For some years it had been a source of surprise to me that a new process, so interesting and so successful as the Huntington-Heberlein treatment of sulphide ores, should have received scarcely any notice or discussion. This lack, however, now appears to be remedied. The suggestion that the subject should be discussed in the _Journal_ is good, as is also that of the designation “Lime-Roasting” for a type-name. Such observations and experiments on the subject as I have had occasion to record have, for many years, figured in my note-books under that heading. Whatever may be the final results of the later processes, now before the metallurgical world or still to come, there can be no doubt whatever that full and exclusive credit must be given to Huntington and Heberlein, not only for first drawing attention to the use of lime, but also for working out and introducing practically the process. It has been a success from the first; and so far as part of it is concerned, it seems to be an absolute and fundamental necessity which later inventors can neither better nor set aside. The other processes, since patented, however good they may be, are simply grafts on this parent stem.