“You have an extraordinary genius for minutiae,” I remarked. “I appreciate their importance. Here is my monograph upon the tracing of footsteps, with some remarks upon the uses of plaster of Paris as a preserver of impresses. Here, too, is a curious little work upon the influence of a trade upon the form of the hand, with lithotypes of the hands of slaters, sailors, cork-cutters, compositors, weavers, and diamond-polishers. That is a matter of great practical interest to the scientific detective – especially in cases of unclaimed bodies, or in discovering the antecedents of criminals".
Arthur Conan Doyle, The Sign of Four














