But for this and other recorded cases of the same kind the Doctor accounted more satisfactorily to himself by his own theory. For though imagination, he said, might explain these perfectly well, (which he fully admitted,) yet it could not explain the horned, nor the tubercular, nor the ruminating cases; nor the case of John Ferguisson, of the parish of Killmelfoord in Argyleshire, who lived eighteen years without taking any other sustenance than water, and must therefore either have been a leech, tortoise, or some other creature capable of being so supported. Nor could any thing so well as his hypothesis explain the cases in which various parts of the human body had been covered with incrustations, which were shed and reproduced in continual succession, a habit retained from some crustaceous stage of existence, and probably acquired in the form of a crab or lobster. Still more remarkable was the case of a German, communicated by Dr. Steyerthall to the Royal Society: this poor man cast his leg by an effort of nature, not by an immediate act of volition as he would have done in his crab or lobster state, for the power had not been retained with the habit, but after long and severe suffering; the limb however at last separated of itself, and the wound healed. Neither, he said, could imagination explain the marvellous and yet well-attested story of the Danish woman who lay in, like Leda, of two eggs. The neighbours who were called in at the delivery, most improperly broke one and found that it contained a yolk and white, to all appearance as in that of a hen, which it also resembled in size. The other, instead of endeavouring to hatch it, they sent to Olaus Wormius, and it is still to be seen at Copenhagen. How, he would ask, was the case of Samuel Chilton, near Bath, to be explained, who used to sleep for weeks and months at a time; but as an old habit of hibernation, acting at irregular times, because it was no longer under the direction of a sane instinct. And how that of the idiot at Ostend, who died at last in consequence of his appetite for iron, no fewer than eight and twenty pieces to the amount of nearly three pounds in weight, having been found in his stomach after death. Who but must acknowledge that he had retained this habit from an ostrich? This poor creature was really ferrivorous. The Doctor though he sometimes pressed into his service a case to which some exceptions might have been taken, would not have classed as a quondam ostrich, the sailor who used to swallow knives for a feat of desperate bravery, and died miserably as might be expected. Nor would he have formed any such conclusion concerning the person of whom Adam Clarke has preserved the following remarkable story, in the words of Dr. Fox who kept a lunatic asylum near Bristol.