It is a common idea among trappers, that the beaver uses his tail for a trowel to flatten down the mud, but this is denied by more observing naturalists, who assert that the tail is merely employed for swimming, although when he is at work with his paws, he may flap it about, but not for any other object. One of the most extraordinary characteristics of the beaver is, that it secretes from certain glands a peculiar odoriferous substance called "castoreum," or "bark-stone" by the trappers. So strangely are the beavers attracted by this substance, that sniffing it up with their nostrils, they will hurry towards it to enjoy the scent. It is consequently the bait used by trappers. The trap is placed five or six inches below the water, and just above it is stuck a stick dipped in bark-stone. The unwary beaver eagerly swims up to it and is caught by the treacherous trap below. Old beavers are, however, generally too cunning; and it is said that on discovering a trap they will carry mud and stones, and drop them over it until it is completely buried. Such was the account which Uncle Denis gave us as we sat round our camp-fire that evening. Dio had listened attentively; he merely observed-- "Dis niggar know all 'bout it." The next morning he invited us to accompany him to the beaver pond, saying, "You shall see what you shall see." Uncle Denis's curiosity had been excited by Dio's mysterious remark, and he accompanied us. Dio produced a bundle of small twigs, which he carried under his arm as we went along. Approaching the pond he begged that we would remain concealed while he went forward. After a little time he summoned us and told us to sit down on the bank of the stream. I had always heard that beavers were the most timid of creatures, and that they would disappear on the approach of human beings, but to our surprise, immediately after Dio had begun to throw in some of his magic twigs, a shoal of beavers popped up from their lodges and rapidly approached, utterly regardless of our presence. So close did they come without perceiving us, that we might have knocked several on the head, but it would probably have been the signal for the disappearance of the whole of them. They appeared to be animated with but one thought, that of carrying off the twigs dipped in their beloved "bark-stone." A few old fellows swam off to a distance and began to devour the twigs, which were evidently much to their taste. Beaver-skins were at that time of great value.