Atony of the bladder is more or less lack of expulsive force, due to failure in power of the muscles of the bladder, the nerves remaining sound. Paralysis is the same condition perhaps more pronounced, but due to central origin. A patient may be unable to pass water in more than a dribbling stream, but if he has true organic stricture or spasm of the deep urethra, the muscular coat of his bladder may perhaps not be to blame for his imperfect urination. The question of atony may be decided in such a case by introducing a catheter of any size that will pass. If there is atony, the stream flows sluggishly from the mouth of the catheter, and toward the end is influenced by the breathing of the patient. If there is no atony, the stream rushes through the catheter, and maintains its force until the last drop flows away. In paralysis and extreme atony the influence of the descent of the diaphragm during inspiration is noticed during the whole course of the flow of the sluggish stream through the catheter. The CAUSES of atony are over-distension of the bladder, voluntary (by persistently neglecting the call to urinate), involuntary retention (from fever, coma, stricture, large prostate), and a certain intrinsic, sometimes inherited, tendency to weakness on the part of the bladder, noticed by some people during their entire lives. Atony is most common, often a part of their malady, in old men with enlarged prostate. Paralysis of the bladder accompanies certain organic changes due to injury or disease in the spinal cord or brain. Both in atony and in paralysis the bladder may be constantly distended to a certain extent, perhaps to its utmost limit, as a passive sac, and the excess of urine over this uniform residuum may dribble away involuntarily {134} (false incontinence), or may be expelled in small portions by repeated acts of urination performed in the ordinary way or by the aid of great straining and assistance from the voluntary contractions of the muscular walls of the abdomen. No condition of incontinence of urine can be considered proved until demonstrated by the passage of a catheter. Both atony and paralysis may get well under proper treatment in favorable cases. Many cases are incurable, but the discomfort they tend to cause may be almost entirely counteracted.