In the absence of any pathognomonic symptom we must consider the history of the case; the symptoms of colic that cease suddenly and are succeeded by cold sweats and tremors; the pulse quick and small and thready, growing weak and more frequent, and at length running down and becoming altogether imperceptible; looking back at the flank and groaning; sometimes crouching with the hind quarters; with or without eructation and vomiting. There is no treatment that can be of any use whatever. Could we be sure of our diagnosis it would be better to destroy the animal at once. Since, however, there is always the possibility of a mistake in diagnosis, we may give powdered opium in 1-dram doses every two or three hours, with the object of keeping the stomach as quiet as possible. OBSTRUCTION COLIC.--The stomach or bowels may be obstructed by accumulations of partly digested feed (fecal matter), by foreign bodies, by displacements, by paralysis, or by abnormal growths. _Impaction of the large intestines._--This is a very common bowel trouble and one which, if not promptly recognized and properly treated, results in death. It is caused by overfeeding, especially of bulky feed containing an excess of indigestible residue; old, dry, hard hay, or stalks when largely fed; deficiency of secretions of the intestinal tracts; lack of water; want of exercise, medicines, etc. Impaction of the large bowels is to be diagnosed by a slight abdominal pain, which may disappear for a day or two to reappear with more violence. The feces are passed somewhat more frequently, but in smaller quantities and drier; the abdomen is full, but not distended with gas; the horse at first is noticed to paw and soon begins to look back at his sides. Probably one of the most characteristic symptoms is the position assumed when down. He lies flat on his side, head and legs extended, occasionally raising his head to look toward his flank; he remains on his side for from five to fifteen minutes at a time. Evidently this position is the one giving the most freedom from pain. He rises at times, walks about the stall, paws, looks at his sides, backs up against the stall, which he presses with his tail, and soon lies down again, assuming his favored position. The intestinal sounds, as heard by applying the ear to the flank, are diminished, or there is no sound, indicating absence of motion of the bowels. The bowels may cease entirely to move. The pressure of the distended intestine upon the bladder may cause the horse to make frequent attempts to urinate. The pulse is but little changed at first, being full and sluggish; later, if this condition is not overcome, it becomes rapid and feeble. Horses may suffer from impaction of the bowels for a week, yet eventually recover, and cases extending two or even three weeks have ended favorably. As a rule, however, they seldom last more than four or five days, many, in fact, dying sooner than this.