again chloroformed. I introduced the lithotrite; but the most careful examination of the bladder failed to discover any fragment of the calculus remaining unpulverized, and but two grains of detritus were sucked out with Clover's syringe; the whole quantity removed weighed one hundred grains.

In both the cases just detailed, it will be perceived that I used the flat-bladed lithotrite of Mr. Henry Thompson. Its power is quite sufficient for medium-sized calculi, and its beautiful construction renders it very safe while feeling for, and breaking the stone. The medical treatment consisted in the administration of a liberal allowance of wine, with plenty of beef tea; and, as a general drink, oatmeal tea, which I have found in those cases more soothing to the urinary passages than decoction of linseed, barley, or gumwater. Whenever mucus appeared in the urine after a sitting, I ordered a mixture, containing infusion of buchu with tincture of hyoscyamus and liquor potassæ; and occasionally, small doses of balsam of copaiba. I introduced a quarter-grain morphine suppository into the rectum after each sitting, and also whenever urethral or vesical irritability existed, with the most marked benefit.

It is evident that as soon as a stone within the bladder has been reduced to fragments, it is most desirable that those fragments should be removed as soon as possible. For those who do not employ the scoop, following the practice of Sir William Fergusson, there remain but two means of effecting this object; one method, deprecating interference with the bladder as much as possible, leaves the fragments to the unaided contractile force of the viscus, trusting they may be expelled with the urine in due time; the other plan, and more trustworthy one, endeavours to promote their removal by washing out the bladder with a strongly-injected stream of water, expecting the return current to carry out much of the detritus stirred up in the bladder. It must, however, have been observed by practical surgeons how often the amount of detritus removed in this way has disappointed their expectations; and it was the failure of the means which I then had at my disposal to remove detritus, which obliged me in my last paper on lithotrity, to place little value on the practice of washing out the bladder. The water thrown in with the ordinary evacuating catheter and syringe returns with but little force, particularly in cases in which the tone of the organ has been in a great measure weakened or lost. It has always been a desideratum to supplement the force of the bladder in the

removal of detritus. The late Sir Philip Crampton saw the necessity of some efficient means of doing so, and not only suggested but employed a most ingenious contrivance, which, in my student days, I saw him use in the Meath Hospital, and which is well described in the number of this Journal for January, 1846, page 22, in the following words:-"The apparatus consists of a strong glass vessel of an oval form, and six or eight inches in length, by three in diameter, and capable of holding about a pint and a-half of water; to this vessel is attached a tube of about half an inch bore, furnished with a stop-cock. The air being exhausted by means of an exhausting syringe, and one of Heurteloup's wide-eyed steel evacuating catheters being introduced into the bladder, it is next attached to the exhausted vessel; the stop-cock is then turned, and a communication being thus established between the bladder and the glass, the pressure of the atmosphere is by this means brought to bear on the bladder, and supplies an expulsive power, which may be increased to any required amount." Figure 4, plate I, gives a tolerably accurate idea of this instrument. It has been drawn from the original one, which my colleague, Mr. P. C. Smyly, kindly placed at my disposal for that purpose.

The instrument of Mr. Clover, of London, for injection of the bladder, and withdrawal of the injected liquid by suction, is such an improvement upon the former means of removing debris by injection, that having found the advantages its employment affords in speedy and safe removal of the fragments of calculi, I consider its use an important auxiliary in the after-treatment of lithotrity. It must be admitted that there can be no more important element in the after-management of a case of lithotrity, or a point more conducive to the success of the operation, than early removal of the detritus, and without injury to the prostate or urethra; and improvements in the surgical appliances for lithotrity are to be much encouraged in this direction as well as in the means of primary comminution of the calculus. By crushing the stone, in the first instance, a comparatively smooth and single calculus is converted into several angular and irregular stones; the bladder, moreover, having become more or less irritated by instrumental interference, the patient is not much better off than he was before the operation. His hopes of relief, therefore, rather depend on the removal of the crushed fragments. Every practical lithotritist will bear me out in saying that the delight of a patient is most remarkable when he sees the fragments; and, on the contrary, his

spirits are depressed when the debris is tardy in making its appearance. I have found the instrument devised by Mr. Clover (to whom the profession is also indebted for an apparatus for the safe administration of chloroform) most efficacious in removing any fragments sufficiently reduced in size to pass through the large catheter attached to his syringe. For those who may not have had an opportunity of seeing it, I have added a drawing, Plate I., Fig. 3; and in explaining it I think I can best do so by quoting Mr. Clover's own description, as given in his letter in The Lancet for May 12th, 1866. He says:-"My instrument consists of a glass cylinder two inches long and two inches wide, having an eight-ounce India rubber ball at one end, and a vulcanite mount at the other, in which is a hole which fits closely to a collar fixed just above the rings of the catheter, so as to allow the catheter to project three quarters of an inch inside the glass vessel."

The instrument that I have been in the habit of using was procured for me from Weiss, of London, by Messrs. Fannin, of Grafton-street. It differs from, but possesses advantages over, that described by Mr. Clover, namely, the mount is of brass attached to the glass, and to it is screwed on the stopper, which has a tube, Fig. 3, the calibre of a No. 12 catheter, fixed to it, and extending into the cylinder about three quarters of an inch. This arrangement renders it unnecessary for the catheter to project into the glass portion of the instrument, and allows the apparatus to be attached to, and detached from the catheter with greater ease.

It has been proposed by my friend Mr. Fleming to improve the instrument by adding an offset to the glass part, resembling that of the ordinary breast-pump-vide Dublin Quarterly Journal of Medical Science for February, 1866, and by Mr. Maunders-vide London Hospital Reports, Vol. III., 1866, page 216. The late Sir Philip Crampton was not unmindful of this addition to his instrument, as will be seen. Plate I., Fig. 1, shows a glass receptacle attached to the brass tube united to a copper cylinder, which he had constructed to bear greater exhaustion than the glass one. I confess that, although ingenious, I cannot see the advantages of such an offset to the glass portion of Mr. Clover's syringe. When the end of the catheter extends sufficiently into the cylinder it renders it most difficult, if not impossible, to force back any fragment that may have been sucked into the instrument. Indeed, in practice I have found that a good deal of debris remains in the

India rubber portion of the apparatus instead of the glass, and certainly if it ever passes beyond the projecting portion of the catheter into the glass it will be retained just as well as with the offset. To the practical surgeon I consider this instrument of Mr. Clover's a great boon, not only to remove detritus after lithotrity, for which he suggested it, but also for the removal of clots of blood from the bladder, as I myself lately found it most efficient in a case of bleeding into this organ, arising from diseased prostate. The catheter should be of the size of No. 12, with a large eye in the concavity of its curve, and provided with a stilette made of gum-elastic (Plate I., Fig. 2), to fill this aperture during its introduction and withdrawal.

The fragments of the calculus removed by lithotrity in the first case were analyzed by my friend Dr. William Daniel Moore, who stated that it was composed of lithic acid. It is unusual, at an advanced period of life, to find a calculus wholly or so largely composed of lithic acid, although in some or other of its salts it is one of the most usual ingredients of all calculi. But while there is no age exempt from the occurrence of urinary concretions, into which lithic acid enters largely, they are, perhaps, more associated with the urinary diseases of earlier than of later life. With this form of calculus there are certain advantages in the performance of lithotrity; there is less apprehension of delay and tediousness in the secondary crushings, because the absence of phosphatic salts indicates an integrity of the mucous membrane of the bladder, and an acid rather than an alkaline condition of the urine, both of which circumstances very much promote the success of any operation implicating the interior of the bladder. In cases where there is reason to believe lithic acid, or its salts, to be undergoing deposition in the bladder, it is dangerous to render the urine alkaline in the hopes of interrupting the formation of a calculus, on account of the tendency which the phosphates exhibit of forming in layers round lithic acid calculi. As soon as the urine is made alkaline, although the deposition of lithic acid may be checked, a layer of triple phosphate will replace it, and the calculus will increase in size as rapidly, if not more so, than before. In the after-treatment of cases of lithic acid calculus it is of importance to prevent a re-deposition in the bladder of this ingredient of the urinary excretion, which will be very liable to occur if the diathesis be not combated. With regard to the urine, it is not necessary to render it more than neutral, for which purpose the waters of Vichy

and the carbonate of lithia are well adapted. It is to be borne in mind that should it be rendered alkaline the phosphates are ever ready to take advantage of a small hemp-seed or pin-head particle of gravel, and upon it, as a nucleus, to initiate a rapidly-growing stone. The object of keeping the urine neutral is to keep the lithic acid in a soluble condition until after its removal from the body. It is also most important to keep the action of the skin healthy, as it has been ascertained that the quantity of lithic acid in the urine is augmented when the cutaneous transpiration is interfered with. Warm clothing, the wearing of flannel or chamois leather next the skin, occasional diaphoretics, and the use of the vapour bath, are means of warding off the excessive formation and deposition of lithic acid concretions which will be worthy of attention after the removal of a calculus of this description. At the same time it will be necessary to endeavour to restore the proper tone of the organs of digestion, and to combat any peculiar form of dyspepsia which may be present, since the lithic acid diathesis is so much due to defective primary assimilation.

ART. III. On the Theory and Principles of the Ophthalmoscope. BY HENRY WILSON, F.R.C.S.I.; L.K.&Q.C.P.I.; Assistant Surgeon to St. Mark's Ophthalmic Hospital; Member of the Royal Irish Academy, &c., &c.

(Continued from Vol. XLII., page 360.)

IN the production of the erect image we employ the ophthalmoscope mirror alone, and make use of the refracting media of the eye itself as a lens; in this examination the observed as well as the observer's eye must be accommodated for distance, and be very close to each other-about two inches; the emergent rays being parallel, will be united on the examiner's retina, and form there an inverted image of the observed fundus; this image, which is magnified by the dioptric apparatus of the observed eye itself, and apparently situate behind the eye, will, however, be mentally perceived as upright. Another mode of producing the erect image consists in the employment of a concave lens, as shown in the