An initial report on the clinical, radiological, and pathological aspects of the lung changes encountered in certain men employed in the manufacture of alumina abrasives has already been published (1). A further report on the chemical aspect of the disease has been read but as yet is unpublished (2). Twelve months have elapsed since the first report was read and during this interval we have had a further period to study in greater detail the symptomatology and clinical features of the disease, as well as serial radiographs. Our initial report presented two groups of cases, well established and early. In the former group there were 23 cases, whereas there are now 34. In the early group there were 12; there are now 38. The classification of well established disease is based on clinical and radiological evidence. All patients with symptoms have changes of moderate to extreme degree demonstrable by x-rays. Others may have few symptoms but the x-ray picture shows a widened mediastinum or marked diaphragmatic adhesions associated with considerable parenchymal shadowing. Our experience has demonstrated that such persons usually progress to a more serious type of disease. In the early cases, on the other hand, symptoms are not present nor do the x-ray films show marked distortion of the diaphragm or mediastinal widening. Occupational History: In reviewing the occupational histories of the well established cases, it is to be noted that the greatest number of employees working in the arc furnace rooms are directly associated with the furnaces as furnace feeders, and it naturally would be expected that from this group one would get the greatest number of cases. We have found, however, that there is a definite hazard encountered by those men who change the furnace pots and also by instructors, who are exposed to sufficient fumes to acquire the disease in certain instances. It has been pointed out in our previous paper that bin men and crane men are also subject to a definite hazard. The summary of exposure for 30 well established cases in men who have been directly associated with the feeding of furnaces and who frequently interchange jobs with hot change men is as follows: Four men gave no history of exposure as furnace feeders. One was a crane operator for five years, and had no other exposure. Another was a hot change man for four years but never had experience feeding the furnaces; in addition, he was a crane operator for six months. A third worked as a hot change man for five years before development of the disease. The fourth patient was a bin man working above the furnaces for three years and two months, in whom serious disease developed. The longest period of exposure was nineteen years, four as a furnace feeder and fifteen as an instructor in the department; the shortest was eighteen months, seven as furnace feeder and eleven as a hot change man.