Only paragraphs 3-8 of the German Imperial Regulations dated February 6, 1900, for Spelter Works are quoted, as the remainder are on precisely similar lines to those for lead smelting works given in full on p. 300. 3. Crushing zinc ore shall not be done except in an apparatus so arranged as to prevent penetration of dust into the workroom. 4. The roasting furnaces as well as the calcining furnaces shall be provided with effective exhaust arrangements for the escaping gases. The occupier shall be responsible for their efficiency during the time the furnace is at work. 5. To avoid dust, ores intended for charging distillation furnaces shall not be stacked in front of or charged into the furnace, or mixed with other material, except in a damp condition. This regulation shall not apply to large so-called Silesian Retorts when in use in the zinc smelter; yet in the case of them also the Higher Authorities may require damping of the charging material if specially injurious to health. 6. Dust, gases and vapours escaping from distillation furnaces shall be caught as near as possible to the point of origin by efficient arrangements and carried out of the smelting rooms. The entrance of the gases from the fires into the smelting room shall be prevented as far as possible by suitable arrangements for drawing them off. 7. Residues shall not be drawn into the smelting room; they shall be caught in closed channels under the furnaces and emptied from these channels at once into waggons placed in passages beneath the distillation rooms. This regulation (where the Higher Authorities approve) shall not apply to existing plants, should it be impossible to make the arrangements mentioned in Reg. 1, or where such additions could only be added by rebuilding at a prohibitive cost. 8. Sieving and packing of by-products obtained by the distillation of zinc (poussière, flue dust) shall not be done except in a special room separate from other workrooms, in accordance with Reg. 1. Sieving shall only be done in an apparatus so arranged as to prevent escape of dust. In _brass casting_, in order to prevent occurrence of brass-founders’ ague, it is necessary that the zinc oxide fumes evolved should be effectively drawn away from the crucible by locally applied exhaust ventilation. General ventilation merely of the room is almost useless, as in casting the fumes rise up into the face of the pourer. Seeing that casting is carried on in different parts of the foundry, it is advisable to connect up the hoods over the moulds by means of metal piping with the exhaust system, or to arrange a flexible duct which can be moved about as occasion requires.