"On November 20, 1868, Schmidt & Co's mill, at St. Louis, burned in a similar manner, the light in this case being in a globe lamp, but the conflagration was, nevertheless, quite as sudden and general as in the first case cited. Other instances of like character have occurred quite recently. And now the query is, What caused the disaster? Whence the combustion? "It has been conjectured that the bran-dust, or fine and dry powder, passing down or up these conductors, may be the kindling cause of the fire in these cases; but bran is not over combustible in itself, nor do we know why it should become so when thus reduced to an impalpable powder. "Another theory is that a gas arises from the transmuting grain, which, excluded from surrounding atmosphere in these close conduits, becomes inflammable, and hence the results, as recited above, whenever a lighted flame is brought in contact therewith. "Be the cause gas or dust, the disaster is the same: and is it not a phenomenon worth studying and remedying, so far as within the province and control of those most interested?" Some similar instances came under our personal observation while adjuster for the Aetna at its western branch. The Star Mills at Mascoutah, Ill., burned about the year 1864. They were grinding middlings. About three o'clock in the morning the miller in charge went up to the chamber (a large box extending through several stories), as he had often done before, to jar the middlings down, they having clogged. He carried a small, open oil lamp, which he placed on a beam, just behind and above his head. He then opened a slide and thrust in a shovel, which started the middlings down with a thump, raising a great dust. As this dust issued in a thin cloud from the slide, it approached and touched the lamp, when instantly, as if it had been coal gas, it flashed, burning the miller's hair and beard, and filling the middlings box with a sheet of flame, which spread with great rapidity and destroyed the mill. A mill at Dover, Ky., had accumulated a large quantity of middlings in an upper story, when the weight caused some sagging, and a man was sent up with a shovel to "even" the bin. His pressure was the "last straw," and the floor under the man broke through, pouring out a cascade of middlings, which flowed down from story to story, filling the mill with its dust. In a very few minutes it reached the boiler room, and the instant it touched the fire it ignited with a flash, and the mills was in flames instantly. It was totally destroyed. In this last named case the gas theory will not apply. The dust was not confined in a spout, but was floating free in the air throughout the mill. The phenomenon was like the others mentioned, and seems to indicate that the fine dust itself, when floating in the air, is the fatal incendiary.