The metropolis of Scotland had been long and frequently excited by statements being made of the disappearance of persons in the lower orders of life, who were suddenly missed, and of whom no subsequent traces could be discovered. Tramps entering the city with their friends were suddenly lost; Irish hay-makers, on their road to the agricultural districts of the Lowlands, in the same manner seemed to vanish from among their companions; and in one instance an idiot, who in Scotland is always looked upon as a harmless playmate for the children, as a welcome guest at every table, and as an object of universal pity, was on a sudden lost from the favourite haunts of his imbecile wanderings. Suspicions of a dreadful character entered the minds of persons, whose duty it was to superintend the police of the town,--suspicions of murder, which might well be supposed to have been excited by the influence of the Almighty, and through which the guilty were eventually discovered and brought to punishment. The occurrence which immediately led to the disclosure of these diabolical crimes was the unaccountable disappearance of a mendicant named Mary Campbell, an Irishwoman, who, after having been seen frequenting the same vicinity for a considerable time, towards the end of October 1829, was suddenly missed. The poor woman happened to have friends, who were not disposed to treat her loss lightly, and a rigid inquiry by the police was the result. An idea was suggested that her body might be found at some of the medical schools in Edinburgh, so justly celebrated for the excellence of the anatomical instruction which they afforded to the pupils; and one day's search testified the truth of the fears which had been excited of her death. Her remains were discovered at the dissecting-room of Dr. Knox, a distinguished anatomist, bearing marks perfectly conclusive of their identity. The poor woman had received a wound upon her ancle, from the kick of a drunken man, the aspect of which was sufficiently well known to enable her former companions to speak with certainty as to the body. The cause of death was now the subject of investigation; and here the deficiency of caution in the purchase of subjects, the necessity of a change in the law with regard to the provision of bodies for dissection, and finally, the certainty of the murder of the deceased, were exemplified. The medical men, by whom the body was examined, gave their firm and decided opinion that suffocation had been the means by which the deceased had been deprived of life,--a means which it was exceedingly unlikely any natural circumstances would have produced. It was evident, therefore, that murder had been resorted to,--it was believed, with a view to secure the body of the wretched woman, in order that it might be sold for dissection.