number of labelled slides, he wrote a single letter on each. The samples of dust taken on the slides could thus be easily referred to the exact spots whence they had been obtained.
Once more we set to work with the microscope, making, now and again, an addition to our lists of discoveries, and, at the end of nearly an hour's strenuous search, every slide had been examined and the lists compared.
"The net result of the examination," said Thorndyke, "is this. The entire coat, inside and out, is evenly powdered with the following substances: Rice-starch in abundance, wheat-starch in less abundance, and smaller quantities of the starches of ginger, pimento and cinnamon; bast fibre of cinnamon, various seed cortices, stone-cells of pimento, cinnamon, cassia and black pepper, with other fragments of similar origin, such as resin-cells and ginger pigment—not turmeric. In addition there are, on the right shoulder and sleeve, traces of cocoa and hops, and on the back below the shoulders a few fragments of graphite. Those are the data; and now, what are the inferences? Remember this is not mere surface dust, but the accumulation of months, beaten into the cloth by repeated brushing—dust that nothing but a vacuum apparatus could extract."
"Evidently," I said, "the particles that are all over the coat represent dust that is floating in the
