_Manufacture of Terne Plates._--The manufacture of lead-coated sheets for roofing purposes is carried on in a few works in South Wales along with the manufacture of tin plates. Lead poisoning in the industry is practically unknown. We can only recollect occurrence of one case, despite the fact that the mixture contains from 65 to 95 per cent. of lead. For cleaning the plates prior to passing them through the concentrated zinc chloride flux into the molten mixture, dilute sulphuric acid is used, and not hydrochloric acid. As to the remarkably different results on health of the two processes, Duckering concludes: “The absence of lead poisoning among terne-plate workers and tinners would appear to be explained by--(1) The use of cleaning agents and a flux of such a nature, and in such a way, as to involve a minimum contact with the tinning metals, and under such conditions as to inhibit extensive interaction between them, and also under such conditions as to inhibit production of fume or vapours, even if any interaction occurs; (2) use of a scientifically prepared flux containing no uncombined acid or excess of water in such a way as to prevent introduction of these substances, or of ferrous compounds coming into intimate contact with the tinning metal; (3) so conducting the operation of tinning that any chlorides possibly adhering to the plates are removed before the plate reappears in the open air, under conditions preventing them from appearing in the air as vapour, but it is very doubtful whether any chlorides could adhere to the plates; and (4) absence of any manual work on the plates before the metallic coating is set and hard. On the other hand, the existence of widespread lead poisoning in tinning of hollow-ware is explained by--(1) Use of cleaning agents and flux in such a way as to bring these materials into intimate contact with the tinning metals under conditions eminently favourable to chemical interaction and vaporization of resultant compounds; (2) use of an unscientifically prepared flux containing a large excess of water and much free acid; (3) so conducting the operations as to favour the escape into the atmosphere of vapours of soluble lead compounds, such as lead chloride, and of metallic lead and soluble lead compounds, carried mechanically by fibres of tow during processes subsequent to tinning, as in wiping; and (4)--a minor point not to be lost sight of--possibility of contamination of the hands by soluble lead compounds, due to manipulating the material with which the articles are wiped. “It should be added that while use of a scientifically prepared flux [(2) above] in hollow-ware tinning would no doubt lessen the possibility of the production of fumes, it is not to be anticipated (unless a flux containing no chlorides were used) that this would do away with lead poisoning. In other words, the method of use is, as indicated above, a far more important factor.”