still, if the urethra be naturally very small, or if any stricture exists, preliminary dilatation is obviously indicated.

The next step may be considered as preparatory also, for it consists in exploring the bladder. A great deal has been said by the opponents of lithotrity, on the inutility and danger of these preliminary explorations; but they are indispensable, unless, indeed, we are content to go to work completely in the dark. They are somewhat analogous to the usual operation of sounding previous to lithotomy; the proceeding, however, is somewhat different, for more precise information is required; or, perhaps, I should rather say, that lithotritists are more careful in ascertaining every particular connected with the state of the bladder, the size of the stone, &c., than lithotomists commonly are. It should be remembered that we have to work for a considerable time with a steel instrument, on perhaps a hard body, in the interior of a small, contractile, and highly sensitive cavity. It is therefore indispensable to obtain some idea of the capacity and contractile power of the bladder before we proceed to break up a stone in this organ. A moderately-sized sound, with a small curve, (this latter circumstance is essential), is introduced into the bladder, and, being rotated, conveys a knowledge of its capacity, while the manner in which the urine escapes will enable us to form some estimate of the contractibility of the organ. Should the bladder be extremely irritable, or, on the contrary, in a state of atony, the operation must be adjourned.

Having thus ascertained that the bladder is in a condition to bear further exploration, we now continue our

examination. When the bladder is contracted the flow of urine must be prevented, and the point of the sound should be directed at once downwards towards the rectum, where the stone is most likely to be found, and the conditions of which part of the bladder, from its relation to the prostate, are most important to be known.

The most experienced surgeons have, from time to time, failed to detect the presence of a stone in the bladder by the usual method of sounding. In doubtful cases of this kind M. Civiale advises us to inject some fluid into the bladder, and to repeat the injections at short intervals, so as to vary the capacity of the organ, keeping it at one time full and the next moment empty; in this way the bladder is excited to contract, its form and capacity are made to change, and it rarely happens that, as the walls of the bladder close round the end of the instrument and the calculus, the latter is not placed in contact with the former.

Certain diseases of the prostate may cause such a depression of the bladder behind the gland, as to render it impossible to discover the stone by the ordinary method of sounding; and the same result may arise from fungous tumours, &c., at the neck of the bladder. In these difficult cases the curve of the sound must be increased, and if this fail, we must have recourse to the lithotrite, which is to be used as a sound. The small size of the calculus has always been an obstacle to its detection with the common sound. If we meet with a case of this kind, it will be necessary to inject two or three ounces of fluid; after which we may introduce the lithotrite, and on opening its blades, from time to time, the calculus is usually seized. Having seized it between

the blades of the instrument, our next endeavour is to ascertain its size; but this can be done only approximatively, for when the calculus is large, or of an oval form, it is quite impossible to measure its size with any degree of accuracy. In 1825, Retoré invented a particular instrument for the purpose of measuring the diameter of calculi (Fig. 46a), but all the necessary information can be ascertained by seizing the stone two or three times between the blades of the lithotrite.

Fig. 46 a.

Fig. 46a.-Retoré's instrument for measuring calculi.

For practical purposes it is not necessary to ascertain the volume of the calculus within a few lines; all we want to know is, whether it be a large or a moderately sized one, and this can generally be ascertained in the manner alluded to.

A knowledge of these various points will be of great assistance to us in the operation which is subsequently to be performed. If we examine the practice of the most successful lithotritist of the present day-one who has performed more than 600 operations-we can hardly attribute his unexampled success to any other cause than the great attention he bestows on these preparatory arrangements. Some surgeons may exceed him in manual dexterity, but none bestow so much care on the medical and accessory points of each case; and hence, I believe, the success of his practice.

CHAPTER III.

THE OPERATION.

SHOULD the explorations described in the preceding chapter have given rise to any degree of irritation, it will be more prudent to defer the operation until such irritation has subsided.

The

On the position of the patient a few words only need be said. The patient is placed on a bed or couch, with the pelvis slightly raised by pillows, so as to bring the most depending part of the bladder on a line with the internal orifice of the urethra. legs are to be separated; the thighs slightly flexed; and the surgeon places himself either in front or on the right side of the patient. Having drawn off the urine with a catheter, he next proceeds to inject slowly some tepid water, continuing until the patient experiences a desire to evacute it; the quantity required generally varies from five to ten ounces. If the fluid be expelled the injection must be repeated with more caution, for we should never think of attempting to operate when the bladder is empty. In some cases the bladder, as M. Civiale observes, is thickened and extremely irritable, tending