Adopt which of these theories the reader may be inclined to, all of them can be brought to bear upon the horse so affected. That cribbing is a habit is seemingly proved by the young horse, stalled next to an old cribber, soon acquiring the custom. That cribbing is provoked by idleness, appears to be in some measure confirmed by the horse never exhibiting the peculiarity before it has been handled and become an occupant of the stable. That it arises from acrimony, induced by the food, is apparently shown by the colt, while at grass, never displaying the symptom. That it will be witnessed in the old horse, when turned out for a month's run at grass, establishes nothing. The temporary visitor to the field may often be seen galloping toward some gate, which, having reached, the horse there commences a long game at crib-biting. This circumstance can settle nothing, except that the digestion is chronically deranged--the stomach, when thus affected, being peculiarly retentive of its morbid condition. Crib-biting consists in resting the upper incisor teeth against any solid or firm substance; a fixed point is thus gained, and, after much effort, a small portion of gas is eructated. The perpetual emissions of heated air is, in man, one of the symptoms attendant on indigestion; and the act, in the horse, appears to be impelled by something stronger than habit; since the animal will leave the most tempting provender for its indulgence. [Illustration: A HORSE IN THE ACT OF CRIB-BITING.] The premonitory symptoms, moreover, seem to declare heartburn to be the cause of this much-dreaded indulgence. The custom is always preceded by licking of the manger. If on that there should be iron, or should any part be cooler than the rest, to that particular spot attention will be paid. The licking of cold substances is a symptom of disordered stomach with other dumb creatures. It is prominently displayed by the dog when the viscus is inflamed. But crib-biting may be prevented, if attacked during the premonitory stage. Any substance, which acts as a stimulant to the stomach, is said to be beneficial. Salt is known as an almost necessary condiment, aiding the healthfulness of human food. The deprivation of salt was an old criminal punishment among the Dutch; and a lump of rock-salt placed in the manger will often enable the horse's digestion to recover its lost tone.