daily for several days will tend to prevent a recurrence of the retention. When the body of the bladder has become benumbed or paralyzed by overdistention, we may seek to restore its tone by doses of one-half a dram of powdered nux vomica repeated daily, and by mustard plaster applied over the loins, on the back part of the belly inferiorly, or between the thighs. Small doses (2 drams) of balsam of copaiba are sometimes useful in imparting tone to the partly paralyzed organ. INCONTINENCE OF URINE (PALSY OF THE NECK OF THE BLADDER). This may occur from disease or injury to the posterior part of the spinal cord or from broken back, and in these cases the tail, and perhaps the hind limbs, are liable to be paralyzed. In this case the urine dribbles away constantly, and the oiled hand in the vagina or rectum will feel the half-filled and flaccid bladder beneath and may easily empty it by pressure. _Treatment._--Treatment is only successful when the cause of the trouble can be remedied. After these (sprains of the back, etc.) have recovered, blisters (mustard) on the loins, the lower part of the abdomen, or between the thighs may be resorted to with success. Two drams of copaiba or of solid extract of belladonna or 2 grains Spanish flies daily may serve to restore the lost tone. These failing, the use of electric currents may still prove successful. URINARY CALCULI (STONE OR GRAVEL). Stone or gravel consists of hard bodies mainly made up of the solid earthy constituents of the urine which have crystallized out of that liquid at some part of the urinary passage, and have remained as small particles (gravel), or have concreted into large masses (stone, calculus). (See Pl. XI, figs. 1, 2, 3.) In cattle it is no uncommon thing to find them distending the practically microscopic tubes in the red substance of the kidney, having been deposited from the urine in the solid form almost as soon as that liquid has been separated from the blood. These stones appear as white objects on the red ground formed by cutting sections of the kidney, and are essentially products of the dry feed of winter, and are most common in working oxen, which are called upon to exhale more water from the lungs and skin than are the slop-fed and inactive cows. Little water being introduced into the body with the feed and considerable being expelled with the breath and perspiration in connection with the active life, the urine becomes small in amount, but having to carry out all waste material from the tissues and the tissue-forming feed it becomes so charged with solids that it is ready to deposit them on the slightest disturbance. If, therefore, a little of the water of such concentrated urine is reabsorbed at any point of the urinary passages the remainder is no longer able to hold the solids in solution, and they are at once precipitated in the solid form as gravel or commencing stone. In cattle, on the other hand,