2. The sides lack the mutual support afforded by an uninterrupted floor of metal; and if made low enough to be readily accessible to fragments (which is important), are, consequently, liable to break, especially should the strain come on one of them. The strength of a fenestrated blade lies in the height of its sides, and is but partially compensated by their breadth; unless the latter is extreme, and the male blade narrow. If it be wide, the corresponding opening not only impairs strength, but delivers large fragments.

3. Now although fragments pass the tubed urethra readily, dust and small debris pass more readily, and first. So that when a fragment has been fortunately seized, the operator loses time if he declines to crush it, as happens when he drives it through a fenestrated blade to be again seized. Although, by the new method, pulverization is no longer essential as before, our aim is still to accomplish a maximum disintegration at each closure of the jaws; and this is better done with a solid upper and lower jaw, than after the fenestration of either of them. A non-impacting instrument is very desirable; but not at the sacrifice of efficient and rapid crushing, or the integrity of the mucous membrane.

I may add, that to prevent impaction, such a projection of the male blade below the female blade as Dr. Keyes has devised and emphasized for this purpose (a description of which indeed occupies a considerable portion of his paper) is quite unnecessary. It is sufficient that the blades of a fenestrated instrument occupy the same level at the outlet.

Again, the heel of the instrument figured in your journal resembles the segment of a circle. Such curved blades admit fragments, and crush them at great disadvantage.

Blades should be

I. As straight,

2. Set at as nearly a right angle with the shaft, 3. As little rounded at the heel,

as is compatible with their introduction.

In my non-fenestrated lithotrite the blades are nearly straight, while the triangular notches deliver on alternate sides. This lateral action not only clears the jaws, but makes their hold very tenacious. It also secures to the blades the incidental advantage, that they grind while they crush.

Dr. Keyes finds my instrument too large, (or as he says, "clumsy.") It is made large with a distinct object, viz., to break larger and harder stones than have been hitherto considered to be within the province of the lithotrite. It comminutes, with safety to the bladder, and without impaction, as no lithotrite hitherto devised has done. The new method of treatment is grounded in the fact that the normal urethra admits larger instruments, and is a readier road to the bladder, than the lithotritist had hitherto recognized. The operator soon becomes not only accustomed to the use of a large lithotrite, but reluctantly foregoes the power it gives him, even when the stone is small. Collin has, however, made a second size.

While the power possessed by this lithotrite and the fact that it does not impact are its more important features, and especially adapt it to the requirements of the method now proposed, almost as useful is the change in its lock. I believe that this will be ultimately adopted by those not already educated to the old system, because it is based upon the readiest movements of the hand and wrist.

But a modification of the jaws and lock of the litho

trite is but an inconsiderable feature of the proposed new method. Rapid work is indeed thereby facilitated; and an empty instrument can be safely withdrawn as often as the operator likes, to relieve the bladder of what will come through the tubes, and so clear the way for more rapid crushing.

A far more important point to the lithotritist, is the comparative harmlessness of long sittings, which was unsuspected, as I think, until the publication of my paper. When this was once under experiment, what was wanted was not so much an improvement of the existing crushing apparatus, as an efficient means of evacuation, capable of removing all the debris at one sitting. For this purpose, the large tubes criticized in your journal are absolutely indispensable. Their use is precisely what makes the new operation practicable, and is, with their manipulation, perhaps its chief innovation. The set of tubes described in my paper ranges from 27 to 31; but they can be procured of any smaller size, and should of course, in any case, be adapted to the previously ascertained calibre of the urethra. It will, however, be found that the efficiency of the tubes diminishes very rapidly with their size, and that cases complicated by stricture, or by small meatus, will require an enlargement by which the introduction of a large tube may be made possible. In such a case as that reported, where the urethra only admitted a No. 20 instrument (French), and in which the writer of course found my largest tubes too large, I should prefer to increase the size of the passage, rather than to attempt extraction through the small calibres formerly in use, even though the tube were otherwise modified as I have recommended. With a normal urethra I do not believe that the tubes supplied by Tiemann will be found any too large.

The change proposed in the new procedure, and its advantages, will appear in a clearer light if we consider the limitations of the usual dilatory method explicitly acknowleged, quite recently, by both Sir Henry Thompson and Sir James Paget. These distinguished authorities gave their opinion that lithotrity should be restricted to stones requiring two or three, or at most three or four sittings, of two or three minutes each. Larger stones in their opinion do better if cut, such adult lithotomy resulting, however, in a mortality of one in three. It should be added that while lithotrity was thus pronounced unsucessful in such cases, all attempts at the immediate evacuation of debris had hitherto resulted in practical failure.

The new method both crushes, and immediately evacuates by the urethra, calculi exceeding in size the limits hitherto affixed to crushing alone. This is done under ether, in a sitting of one or two hours duration, or even longer. So far, its results have been better than could have been anticipated,-being sixteen or seventeen cases of complete evacuation with but one death, — against one in thirteen by the usual method. Several of these patients would have been, by accepted rules, subjected to lithotomy, and therefore to a risk equal to one death in three cases. I cannot but think, that with due care in its application, the method now proposed will be found to yield results at least as favorable as those before obtained.

The following are the chief points connected with the modified lithotrity:

1. The calculus, although not necessarily pulverized, is crushed as rapidly and completely as is practicable. The dust and fragments are immediately evacuated, and a serious source of irritation is thus removed.

2. This can be generally effected in a single opera

tion.

3. This operation

performed of course under ether—may be, if necessary, of one or two hours duration, or even longer.

4. The method applies to larger stones than have been hitherto considered to lie within the province of the lithotritist. It also applies to nuclei, phosphatic deposits, and foreign bodies.

5. Evacuation is best accomplished by a large tube, preferably straight,— with a distal orifice, arranged to facilitate its introduction and, during suction, to repel the bladder wall; - and by an elastic exhausting bulb which acts partly as a syphon. Below it is a glass receptacle for debris.

6. The best size for the tube is the largest the urethra will admit.

7. Such a tube is introduced with facility, if passed vertically as far as it will go towards the anus before changing its direction, and afterwards directed almost horizontally, and turned like a corkscrew through the triangular ligament. The first part of this rule applies also to the introduction of a lithotrite, and even a curved catheter.

8. A small meatus should be enlarged, or a stricture divulsed to allow the passage of a large tube.

9. Unless the bladder be small, a large and powerful lithotrite is better than a small one.

10. That this may have room for action, the escaping water should be replaced occasionally, by a tube inserted a few inches in the urethra by the side of the lithotrite.

II. To save time, and also to prevent undue distension of the vesical neck, a non-impacting lithotrite is