Dust is an accumulation of debris in the form of powder. The types of dust are inorganic dusts, which include all the dusts of inorganic chemical substances and elements; organic dusts, which are composed of vegetable particles and animal debris; and professional dusts, which are related to the bearer's profession or occupation. The places where dust may be collected are clothes, pockets, footwear, linen, skin, hair, nails, eyebrows, ears, nostrils, weapons, and vehicles. The types of dust likely to be found in each of these places and ways to collect the dust for analysis are described. The author then summarizes six cases in which the analysis of dusts helped in convictions of offenders. The author notes that limited space for this article did not permit detailed descriptions of the technique of gathering and analyzing the various dusts. He advises that dust analysis as a method of identifying suspects will not come into its own until it has been placed on a systematized basis. This will require development of the technique of microchemistry and the habitual practice of gathering and examining dusts.