With regard to the action of spasm, all we know of it is theoretical; but experience every day furnishes instances of its occurrence. Spasmodic stricture is generally seated at the neck of the bladder, and may occur to persons in good health, from exposure to wet or cold; from some digestive derangement; from long retention of the urine, particularly while walking, owing to the absence of public urinals; or to violent horse exercise; but more frequently does it happen to those young men who, when suffering from gleet or gonorrhœa, imperfectly or only partially cured, are tempted to commit an excess in wine, spirits, or other strong drinks. Surrounded by jovial society, glassful after glassful is swallowed, each one to be the last. The patient, with his bladder full to repletion, scarcely able to retain his water, yet probably “_going_” every moment, represses his desire until the party breaks up, when, on encountering the cold air, he finds himself unable to void even a drop, or if so, but with extreme difficulty. The greater the effort, and the more determined the straining, the greater is the impossibility, and unless relief should be afforded, the most alarming consequences may ensue. The rationale is this: the patient, opposing the action of the muscles of the bladder, by contracting those of the urethra, they (the latter), from irritation, become spasmodically contracted. The urine, by the powerful action of the muscles of the bladder, is forced against the contracted portion of the urethra; and by its irritation increases the mischief. Where neglected, or unless the spasms yield, extravasation will take place, mortification ensue, and death follow. The urethra is situated at the under part of the penis, and is embraced by a substance called the _corpus spongiosum_; it (the urethra) consists of several different layers or coats—the inner, the one continuous with that lining the bladder, which possesses the power of secreting a mucous fluid, and the other made up of muscular fibres, which give to the urethra the power of contracting and dilating, that regulates the flowing or jetting of the fluid which has to pass through it. The mucous membrane of the urethra is of a highly sensitive nature, and more so in some parts than in others, as, for instance, in the membranous and bulbous portion of the canal; and hence it will be found, that those are the parts most liable to disease. The mucous membrane has several openings called _lacunæ_, for the furnishing a particular fluid to moisten and lubricate the urinary tube: these also are frequently the seat of disease. These are seen in the drawing on page 50. In passing a bougie in contracted and irritable urethra, it sometimes enters the opening marked B, and if violence be used in propelling the instrument, false passages are made.