=Brass[19].=--The malady the brass caster has suffered from in the past is _par excellence_ brassfounders’ ague. Lead, however, is introduced (rarely exceeding 10 per cent.) for the purpose of softening the alloy of copper and zinc. Of 77 cases of lead poisoning in the ten years 1900-1909 included under the heading “Brass,” 38 were polishers, 28 casters and others, and 11 chandelier fitters. Cases occur among the casters probably from inhalation of the fumes in pouring, and among the polishers from inhalation of the small proportion of lead in the dust given off in the absence of adequate exhaust. In a factory where there were two emery wheels, one with a hood and fan to carry the dust away, while the other remained unprotected, the worker at the unguarded wheel suffered from lead poisoning. In filing and dressing the article is held in a clamp with leaden claws, which gradually become worn away, just as does the lead bed used by the file-cutter. This may account for the poisoning reported among filers and dressers. A sample of dust taken from under a calico mop for brass polishing was found in the Government laboratory to contain 2·1 per cent. of lead. The joints of chandelier fittings are sealed with a white lead paste. Instead of always testing the completeness of the seal by means of an air pump and pressure gauge, the fitter frequently tests it by applying his lips to the unsealed end and blowing through the pipe. All the cases among chandelier fitters are caused in this way--perhaps the clearest instance of poisoning by absorption through the alimentary canal, as distinguished from absorption through the lungs, that can be cited. While use of an air pump and immersion of the joint in water or pressure gauge only is an entire protection, and should be provided wherever this work is done, constant supervision as to its use is called for. The sealing of the joint can be done with a material known as “caulkite,” containing neither white nor red lead. For references, see end of Chapter XVII. CHAPTER XVI DESCRIPTION OF PROCESSES--_Continued_ =Manufacture of White Lead[20].=--The usual method in this country is that known as the “Dutch process,” although the German chamber process, precipitation processes, and others, are all practised.