The briquetting machine samples were taken from the platform where all the ore and fluxes are mixed before briquetting. The results obtained here were as follows: Dust 0·95715 grain of lead per cubic foot. Fume, or fine dust that passed through filter 0·01314 „ „ „ The reason for these high results was owing to dust raised when waggons of ore were tipped prior to mixing. Assuming that 20 cubic inches of air pass in and out of the lungs at each respiration, a man in eight hours would inhale and exhale 94·4 cubic feet. This amount of air, inhaled at the position in the cupola where the sample was taken, would contain 7·3818 grains of lead; at the lead well, 5·3064 grains; and at the briquetting machines, 91·5953 grains. Although the condition of the air where the men actually worked must have contained much less than these amounts, the analyses quite serve to explain the heavy incidence. Collis[5] quotes the following analysis of dust and fumes from Hofman’s “Metallurgy of Lead.” LEAD SMELTING: ANALYSES OF DUST AND FUMES (FROM HOFMAN’S “METALLURGY OF LEAD”). +--------------------------------+---------------------------------+ | | Percentage of-- | | +------+------+-----+------+------+ | | | Arse-| | Lead | Lead | | | Ar- | nious| |Monox-| Sul- | | Material Analysed. |senic.|Oxide.|Lead.| ide. |phate.| +--------------------------------+------+------+-----+------+------+ | (1) | (2) | (3) | (4) | (5) | (6) | |All dust collected in ten years,| -- | -- | 25·6| -- | -- | |average | | | | | | | Dust from-- | | | | | | | Downcomers of eleven blast | -- | -- | 47·5| -- | -- | | furnaces | | | | | | | Roof of blast-furnace building| -- | -- | 27·1| -- | -- | | Fumes from-- | | | | | | | Slag pot while boiling | -- | 4·8 | -- | 41·0 | 26·2 | | Reverberatory settling furnace| 2·3 | -- | -- | 31·0 | -- | | Flue dust-- | | | | | | | Friedrichshütte, Silesia | -- | -- | -- | 62·8 | -- | | { A | 7·5 | -- | 26·2| -- | -- | | Freiberg, Saxony { B | 37·5 | -- | 21·3| -- | -- | | { C | 46·4 | -- | 16·2| -- | -- | | Pribram, Bohemia | -- | 1·0 | -- | 45·5 | -- | +--------------------------------+------+------+-----+------+------+