ABSTRACT
In 1913 it was still thought that any kind of dust was associated with increased risk of pulmonary tuberculosis. The first beams of dawn on this twilight are to be found in evidence placed before the Royal Commission on Metalliferous Mines and Quarries, and finally published in 1914. The earliest experimental work, therefore, had to be directed towards elucidating the connection between silica and the tubercle bacillus. Pulmonary infection, in general, may exacerbate the effects of inhaled silica. Work had also been progressing on methods of producing fibrosis. By 1950 King et al. were producing dense, round, collagenous nodules with a well-controlled standardized inhalation procedure, which has been little altered to this day. Kettle among others attempted to take a short cut by introducing suspensions of dust directly into the lungs, but both he and Gardner believed that “a single flooding of the lungs with an overwhelming dose of dust can have no relation to the continuous inhalation of small quantities.
