In this small industry in the past the poisoning must have been considerable. In 1898 nineteen cases were reported. Reference to the table on p. 47 shows that the number now is greatly reduced. Those reported are generally cases which have ended fatally from the sequelæ of lead poisoning contracted many years previously. Stained-glass painting--a form of vitreous enamelling--very rarely gives rise to poisoning, as no dust is generated (see vitreous enamelling for use of aerograph in glass-painting). =Paints and Colours[33].=--Most of the cases have occurred in the manufacture of white-lead paint, although manufacture of chromate of lead and of Brunswick greens (barytes with which Prussian blue and chrome yellows are mixed) account for several. The following table shows the precise occupation of persons affected, the number of cases distributed according to precise occupation, and the proportion of these to the total in 225 cases which were closely examined: +------------------------------------+------------+--------------+ | | Number of | | | | Cases | Proportion of| | Precise Occupation | in each |Cases to Total| | of Person affected. |Subdivision.| (per Cent.). | +------------------------------------+------------+--------------+ |Mixing and grinding (mainly of white| 144 | 64·0 | |lead) | | | |Packing (mainly of red lead) | 19 | 8·4 | |Sieving | 2 | 0·9 | |Manufacture of chrome yellow | 22 | 9·8 | |Colour house and filters | 16 | 7·2 | |Painting and stencilling | 6 | 2·7 | |Other processes | 16 | 7·0 | +------------------------------------+------------+--------------+ Knowing the conditions of work, we can confidently assert that the poison must have entered the system in the form of dust in at least 90·0 per cent. of the cases, and in the remainder the possibility of dust having been the cause is not excluded. In a small factory the cask of white lead is broken and the material scooped out into a pail. Scales are at hand, and when the amount of lead removed weighs half a hundredweight the contents of the pail are discharged either into a cylindrical pug-mill or into the pan of an edge-runner to be mixed with oil. In large factories the dry white lead is generally shovelled directly from the cask down openings or shoots in the floor to the grinding mills below.