The system of fosterage, which consisted in the mutual exchange of children for the purpose of being nursed and bred, was a custom peculiar to the Scots and Irish, who were wont to allege that there was no love or faith in the world like that which existed between foster-brethren; so Rob departed in confidence on his important mission with a herd worth twenty thousand Scottish merks. Prior to his leaving Inversnaid, Paul Crubach had come there, and sprinkled all the cattle with water from his holy well. On such occasions he was always provided with certain flint arrow-heads, which he had found where a battle had been fought, long, long ago. These _elfshots_ he duly dipped in the water of his well, and then sprinkled it over the herd to prevent any spell an evil eye, or another elfshot, might cast upon them before they reached the great market at "Merry Carlisle." CHAPTER XII. THE GIPSIES. The trade of cattle-dealing was liable at that time, as at every other, to sudden depressions and miscalculations; thus, on his arrival at Carlisle, Rob Roy--unfortunately for the success of the joint speculation in which he was engaged--found the southern markets, where Highland cattle had been so long in great demand, completely overstocked. Many other speculators were now in the field. The prices fell lower than they had ever been before, and he was compelled to dispose of the whole stock of cattle far below prime cost. As his herds diminished, he gradually sent all his drovers and gillies home to the Highlands. The last he despatched was Greumoch MacGregor, with whom he entrusted a letter (dated from an hostelry in Castle Street, where he lodged) addressed to the Duke of Montrose, detailing their mutual loss. When the last cow was sold, Rob secured the money which remained for the Duke and himself in his sporan, as the pouch worn in front of the kilt is named. It was made of the skin of an otter, shot by himself in the Dochart, and was adorned by its face and claws, and closed by a curious steel clasp. With his pistols carefully primed and loaded (as the roads were then infested by footpads, mounted highwaymen, and gipsies), he left Carlisle by the Scottish gate, and in very low spirits took his homeward way, mounted on a stout little Highland horse. Carlisle was then, and for long after, girt by walls and towers as a defence against the Scots, whom the English could scarcely view yet as fellow-subjects.