or as encouragements to proceed. This superstitious belief in luck is still prevalent. A notorious banknote forger in France carefully abstained from counterfeiting notes of two values, those for 500 francs and 2,000 francs, being convinced that they would bring him into trouble. Thieves, it has been noticed, generally follow one line of business, because a first essay in it was successful. The man who steals coats steals them continually; once a horse thief always a horse thief; the forger sticks to his own line, as do the pickpocket, the burglar, and the performer of the confidence trick. The burglar dislikes extremely the use of any tools or instruments but his own; he generally believes that another man's false keys, jemmies, and so forth, would bring him bad luck. Only in matter-of-fact America does the cracksman rise superior to superstition. There a good business is done by certain people who lend housebreaking tools on hire. Instinct, aboriginal and animal, has helped at times to bring criminals to justice. The mediæval story of the dog of Montargis may be mere fable, but it rests on historic tradition that after Macaire had murdered Aubry de Montdidier in the forest of Bondy, the extraordinary aversion shown by the dog to Macaire first aroused suspicion, and led to the ordeal of mortal combat, in which the dog triumphed. [Illustration: SUMATRAN THIEVES' CALENDAR (BRITISH MUSEUM) FOR CALCULATING LUCKY DAYS.] It has been sometimes suggested that the instinct of animals might be further utilised in the pursuit of criminals. Something more than the well-known unerring chase of the bloodhound might be got from the marvellous intelligence of dogs. We shall see how the strange restlessness of the dog owned by Wainwright's manager in the Whitechapel Road nearly led to the discovery of the murdered Harriet Lane's remains. The clever beast was perpetually scratching at the floor beneath which the poor woman was buried, and his inconvenient restlessness no doubt led to his own destruction, for Wainwright is said to have made away with the dog. In India the idea of using the pariah dog for the purpose of smelling out buried bodies has been often put forward. Dogs would avail little, however, if the corpse lay at a great depth below ground, and hence the suggestion to draw upon the keener sense, exercised over a wider range above and below ground, of the vulture. This foul bird is commonly believed to be untameable, but it might assist unconsciously. Vultures are much given to perching upon the same tree near every Indian station, and close observation might reveal the direction of their flight. Their presence at any particular spot would constitute fair grounds for suspicion that they were after carrion. Indian police experience records many cases of the discovery of bodies through the agency of kites, vultures, crows, and scavenging wild beasts. The howling of a jackal has given the clue; in one remarkable case the body