III. Provides for the method of permitting the exceptions named above in sections 2 and 3, and makes it a condition of reduction in cubic air space for each person employed as type founder or compositor that there shall be adequate mechanical ventilation for regulating temperature and carrying off products of combustion from workrooms. Ceramic Industry (See also pp. 135-8.) A complete substitute for lead in glazes seems as yet impossible on technical grounds, as glaze containing lead has qualities which cannot be obtained without its use. In small works the technique necessary for the production of leadless glazes (special kinds of stoves) cannot be expected, especially as those carrying on a small industry lack the necessary knowledge of how to be able to dispense with the use of lead glazes and substitute leadless materials without complete alteration in their methods of manufacture. And yet discontinuance or the utmost possible limitation of the use of lead glazes and colours is most urgently needed in all small ceramic workshops, as they are not in a position to put in localised exhaust ventilation, &c., which is possible in large factories. Observance of even the simplest hygienic measures can scarcely be obtained. Consequently very severe cases of lead poisoning are met with in small works. An effort in the direction of discontinuance of lead glazes was made in Bohemia, where (at the cost of the State) technical instruction was given by an expert on the preparation of leadless glazes especially in districts where the industry was carried on in the homes of the workers. This procedure, extension of which is expected, had good results. Many have demanded, in view of the possibility of substituting leadless for lead glazes, the total prohibition of lead. Such is the view of the Dutch inspector De Vooys; Teleky and Chyzer share the view expressed so far as the small industry is concerned, since the practicability of the change has been demonstrated. English authorities (Thorpe, Oliver) propose diminution of the lead in the glaze in such a way that on shaking with weak acid not more than a specified small quantity shall be dissolved (Thorpe test). In my opinion such a measure is hardly enough for the small industry. I do not expect much good from obligatory use of fritted glazes. In addition to earthenware, manufacture of tiles and bricks leads not infrequently to cases of lead poisoning from use of lead glaze. The following measures apply to the larger ceramic works. Since risk is considerable, not only in glost placing but also in grinding, ware-cleaning, &c., closed ball mills in grinding and locally applied exhaust ventilation in ware-cleaning operations, &c., must be arranged. Personal cleanliness and proper equipment of a factory in all the essentials insisted on on pp. 226-9 are important, but nothing can take the place of efficient locally applied ventilation.