He attains this object by means of an instrument composed of two grooved blades, united about one inch from their apex, into a conical sound, which at its apex is about the size of a No. 2 bougie. This is passed into the bladder, and the grooved blades are separated to any extent that is desired by passing down between them a straight rod equal in size of a No. 8, 10, or 12, bougie. To guide this properly it is made hollow, and it is passed down over a central wire which lies between the grooved blades of the instrument and is welded to the apex. A great improvement is effected on Mr. Holt's later instruments by this wire being made hollow, and fitted with a stilette, for by this means we can with certainty ascertain whether or not the instrument has been passed into the bladder. This instrument, which is an improvement upon one invented by Perrève nearly forty years ago, has been used on very many occasions by Mr. Holt and others with success. The risk to life, if the case be properly managed, is trifling, but, like every other means of treating stricture, it has the objection that the stricture is liable to recur, unless bougies be passed at intervals for months and years. Sir Henry Thompson has introduced and described another very ingenious instrument for the same purpose, constructed on somewhat similar principles. His account of it, to which I must refer, will be found in Holmes's _System of Surgery_, 1st ed. vol. iv. p. 399. 2. INTERNAL DIVISION OF STRICTURE is a mode of treatment which by many surgeons is highly disapproved, yet of late years it has been more used than formerly, especially in resilient strictures. It may be done in two ways:-- (1.) _From before backwards._--This method, to be at all admissible, requires a guide to be previously passed; a lancet-shaped blade may then be slipped down a groove in this guide till the stricture is divided. This is least objectionable in cases of stricture close to the meatus. (2.) _From behind forwards._--To make the incision thus, it is of course necessary that the stricture should be so far dilatable as to admit an instrument the point of which is large enough to contain the blade by which the stricture is to be divided. This will be found to be at least equal in size to a No. 3 or No. 4 catheter. In many instruments it is much larger.