It is a mistake to suppose that any ointments smeared upon a sound do good in this condition. Mercurial, belladonna, and other ointments are used, but they are all and entirely rubbed off the sound before it reaches the deep urethra, and their good effect probably resides solely in the imagination of the physician and the credulity of the patient. Ointments are undoubtedly of service in some obstinate cases, notably strong tannic-acid mixtures, and sometimes iodoform, but these cannot be carried to the deep urethra by being rubbed upon a sound. The cupped sound may be used to effect this very neatly, the little cups on the sides of the {126} curve of the sound being filled with the ointment which it is proposed to carry down and apply to the affected spot. A few drops of a mild nitrate-of-silver injection also give decided good results in some cases. The solution should vary between two and ten grains in the ounce of water, and may be accurately applied by means of a Bigelow or an Ultzmann syringe, a few drops being thrown into the membranous urethra. After the application, which should be made only when the patient has a full bladder, urination will wash out the canal and good effects may be looked for--not immediately, as after sounding, but after the irritation produced by the stimulating application has subsided. Acute Cystitis. Acute cystitis sometimes involves only the neck of the bladder; in other cases the whole mucous lining of the bladder is included in the morbid process. The causes of acute cystitis may be grouped under six heads: 1. Traumatic.--Under this head may be ranged all injuries from without, with or without fracture of the pelvic bones--wounds, rupture of the bladder, the pressure of the child's head during labor; injuries from within, as during the use of instruments, by stone, or pedunculated tumor. The list may be increased by such chemical traumatisms as those produced by ammoniacal urine in cases of atony or paralysis, by excessively acid urine in neurotic conditions of the neck of the bladder. Such chemical causes, it will be observed, commonly act in conjunction with another cause. Irritating injections without any co-operative cause are capable of lighting up acute cystitis. 2. Extension of neighboring inflammation--gonorrhoeal cystitis and that attending prostatic inflammation, pelvic abscess, pelvic cellulitis, peritonitis from neoplasms growing at the vesical neck, tubercle, cancer, etc. 3. Medicinal--from cantharides, sometimes cubebs or turpentine. 4. Specific--in diphtheritic, puerperal, septicæmic conditions. 5. The influence of cold when chronic inflammation already exists. 6. Neurotic--actual, from extreme and long-continued neuralgia of the vesical neck; reflex, from irritation at a distance, tight meatus, stricture, inflammation of the seminal vesicles, kidney irritations.