_Printing as from Engraved Plates._--Professor Ray Lankester kindly sent me his method of taking prints with water colours. "You take a watery brushful or two of the paint and rub it over the hands, rubbing one hand against the other until they feel sticky. A _thin_ paper (tissue is best) placed on an oval cushion the shape of the hand, should be ready, and the hand pressed not too firmly on to it. I enclose a rough sample, done without a cushion. You require a cushion for the hollow of the hand, and the paint must be rubbed by the two hands until they feel sticky, not watery." This is the process of printing from engravings, the ink being removed from the ridges, and lying in the furrows. Blood can be used in the same way. The following is extracted from an article by Dr. Louis Robinson in the _Nineteenth Century_, May 1892, p. 303:-- "I found that direct prints of the infant's feet on paper would answer much better [than photography]. After trying various methods I found that the best results could be got by covering the foot by means of a soft stencil brush with a composition of lampblack, soap, syrup, and blue-black ink; wiping it gently from heel to toe with a smoothly-folded silk handkerchief to remove the superfluous pigment, and then applying a moderately flexible paper, supported on a soft pad, direct to the foot." A curious method with paper and ordinary writing ink, lately contrived by Dr. Forgeot, is analogous to lithography. He has described in one of the many interesting pamphlets published by the "Laboratoire d'Anthropologie Criminelle" of Lyon (_Stenheil_, 2 Rue Casimir-Delavigne, Paris), his new process of rendering visible the previously invisible details of such faint finger prints as thieves may have left on anything they have handled, the object being to show how evidence may sometimes be obtained for their identification. It is well known that pressure of the hand on the polished surface of glass or metal leaves a latent image very difficult to destroy, and which may be rendered visible by suitable applications, but few probably have suspected that this may be the case, to a considerable degree, with ordinary paper. Dr. Forgeot has shown that if a slightly greasy hand, such for example as a hand that has just been passed through the hair, be pressed on clean paper, and if common ink be afterwards brushed lightly over the paper, it will refuse to lie thickly on the greasy parts, and that the result will be a very fair picture of the minute markings on the fingers. He has even used these productions as negatives, and printed good photographs from them. He has also sent me a photographic print made from a piece of glass which had been exposed to the vapour of hydrofluoric acid, after having been touched by a greasy hand. I have made many trials of his method with considerable success. It affords a way of obtaining serviceable impressions in the absence of better means. Dr.