_Plain earthenware_ is either not glazed or salt glazed; only when decorated does it sometimes receive an acid lead glaze. _Porcelain_ receives a leadless glaze of difficultly fusible silicate (quartz sand, china clay, felspar). Risk is here confined to painting with lead fluxes (enamel colours) containing lead. These fluxes are readily fusible glasses made of silicic acid, boric acid, lead oxide, and alkalis, and contain much lead (60-80 per cent. of red lead). In the _glass industry_ lead poisoning may occur from use of red lead as one of the essential ingredients. In Great Britain, in the years 1900-9, forty-eight cases were reported in glass polishing from use of putty powder. LETTERPRESS PRINTING, ETC. Type metal consists of about 67 per cent. lead, 27 per cent. antimony, and 6 per cent. tin, but sometimes of 75 per cent. lead, 23 per cent. antimony, and 2 per cent. tin. The actual printer comes least of all in contact with lead. Use of lead colours (white lead, chromate of lead, &c.) may be a source of danger, especially in the preparation of printing inks from them and in cleaning the printing rolls. A further, if slight, danger arises from the use of bronze powder consisting of copper, zinc, and tin. The two last-named metals contain from 0·1 to 0·5 per cent. of lead, and in the application and brushing off of the bronze there is a slight risk. The compositor is exposed to constant danger from handling the type and disturbing the dust in the cases. This dust may contain from 15 to 38 per cent. of lead. Blowing the dust out of the cases with bellows is especially dangerous, and want of cleanliness (eating and smoking in the workroom) contributes to the risk. Type founders and persons engaged in rubbing and preparing the type suffer. Introduction of type-casting machines (linotype, monotype) has lessened the danger considerably. No lead fumes are developed, as a temperature sufficiently high to produce them is never reached. In all the processes, therefore, it is lead dust which has to be considered. The following figures of the Imperial Statistical Office as to occurrence of lead poisoning among printers in Vienna indicate the relative danger: +---------------------------+-----------+-----------+----------+ |Occupation. |Average No.|Average No.|Percentage| | |of Members,| of Cases, | of Cases,| | |1901-1906. |1901-1906. |1901-1906.| +---------------------------+-----------+-----------+----------+ |Compositors | 3182 | 90·3 | 2·8 | |Printers | 809 | 20·3 | 2·4 | |Casters and Stereotypers | 241 | 15·8 | 6·6 | |Females employed in casting| 74 | 8·17 | 10·8 | +---------------------------+-----------+-----------+----------+