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2 per cent, ore, and at Scharfenburgh, on the Elbe, f per cent. ore. At both places they are obtaining a profit from both zinc-blende and from iron-pyrites ; and at the latter the tailings are mixed with cement, and made into drain-pipes. All by-products having a value, and wages only ranging from Is. to 2s. per day, very poor ore can be handled profitably. "In Spain the plant is working on an intimate mixture of siderlrte, zinc-blende, and galena; in Algeria, on galena-ore ; in Norway, on auriferous pyrites ; elsewhere, on manganese-ore. " *\t Laurium, Luhrig is erecting a plant to cost £150,000 to deal with ore containing about 12 per cent, lead, 10 percent, zinc, and from Boz. to 12oz. of silver. This plant is in three divisions, one for oxidized ores, one for sulphide-ore, and one for old tailings. " The Humboldt system and all others appear to be giving way to the Liihrig system all over Europe. Quite lately, and since I left Europe, a French company has ordered a Luhrig plant on a large scale for their mines in France ; and the directors told Mr. Lempriere that they had satisfied themselves that the Humboldt plant was neither so efficient nor so economical. They had therefore decided to discard it in favour of the Luhrig. " A plant on the Luhrig system is now being erected in Colorado, United States of America, and a large one is to be erected, on some abandoned lead- and arsenic-mines in Wales. " The Government of Saxony has introduced the system at several of the Fiscal Boyal mines, and a report has been made by professional men for the Government. This report concludes with, ' All difficulty in economical separation of ores, and in dealing with slimes, has been overcome by Mr. C. Luhrig, and the thanks of the community are due to him.' I may here remark that this is no new invention, but a system evolved from a thorough knowledge of all that is required in ore-dressing, and a long acquaintance with dressing plants and appliances in Saxony, the home of ore-dressing. The inventor has been gradually developing his system and appliances for twenty years. " The Plant. " One hundred and fifty plants, inclusive of local plants, had been erected up to December, 1889; many more have been built since. The plants are all made double—that is, one-half on one side of the building, and the other half on the opposite side; thus two classes of ore may be dressed simultaneously. The machinery is made under Luhrig's own eyes, and erected by his engineers, who run it until some one is educated up to taking charge. "The main features are good system; space round all the machines or appliances; saving labour wherever possible; losing but little water, merely the evaporation, and that which does not drain from the tailings ; making an almost clean product in the principal minerals, and a middle product at each successive reduction in size, until the residue is reduced to slime, and at all stages working continuously; and finally, recovery of sludge, and filtering the water so that it may be used continuously. When arranging the plant, special attention is paid to grading, according to size; to gradual reduction for the jigging appliances ; and to grading according to relative weights for the slimes. " Too much importance cannot be attached to the fact that this system solves the important problem of how to construct a plant by which the reduction of the ore takes place gradually, thus avoiding unnecessary crushing of fine particles of clean ore, and only crashing fine such particles as cannot be brought up to a sufficiently high percentage of metal without such further reduction. Even with pyritous gold-ores it may be found better to adopt gradual reduction and concentration, so as to remove the whole of the pyrites before any amalgamation of the free gold is attempted. " Treatment through Liihrig System. " After hand-picking, if such be necessary, the whole of the ore is fixed on a screen of about 1-J-in. mesh, the larger pieces passing over this to the rock-breaker. The troughs and tails from the screen and rock-breaker then pass to sizing-drums, which separate the finer stuff from that not yet sufficiently reduced by the rock-breakers. Material of about Jin. and under fin. is generally passed direct to jigs to get rid of worthless material only. The partially concentrated material is then passed through rolls and mills. The larger pieces or tails from the sizing-dram pass on to picking-tables, or continuous conveyors, where rich ore and worthless material is picked out by hand, the mixed ore passing through rolls and mills for further reduction. The ore from the mills passes into another set of sizing-drums, from which the finer sizes pass on to jigs direct, whilst the tails or larger sizes pass to finer rolls and mills for further reduction. In this way the reduction takes place gradually and automatically, the ore gravitates through the various mills and screens, and generally a fourth set of rolls, screens, and jigs is employed before the poorer mixed ore goes to the stamps for final reduction. " The jigs in the Luhrig system are generally built in four or five compartments, giving the following concentrated products : For instance, galena, arsenical pyrites, iron-pyrites, zinc-blende, and a middle product in which galena generally preponderates, or in which the gangue is very finely impregnated with ore. The middle product is passed through a set of rolls and again concentrated, or more frequently is stamped and concentrated. " Slimes through the Luhrig System. " I wish to draw your special attention to this part of the system, because it is that which may be economically applied to the treatment of auriferous tailings and slimes, and be the method by which miners and labourers past active work underground may be provided with remunerative labour for many years to come, and the opening of a new and profitable industry on the goldfields of Victoria be provided. There is no occasion for me to dilate upon the advantages to be obtained from a satisfactory process for obtaining the bulk of the gold from tailings and slimes, or upon the quantity and value in the waste heaps on the goldfields. You probably know as much as, or even more than, Ido upon this subject. The concentration of the sand and slimes commences with the