There is also present spasm of the sphincter ani, and in severe cases the irritation extends to the bladder and urethra. It sometimes lays the foundation of Abscess in Perinco and Fistula. On account of the continued irritation kept up by the daily discharge of the fæces, the fissured or ulcerated membrane heals with great difficulty, unless recourse be had to the knife, and the sphincter ani be completely cut through.* In mild cases it may be sufficient to apply, within the anus, two or three times a day, a portion of the following ointment:Hydrarg. oxydi cinerei, 3j. Cerati cetacei, 3vj.

Pulveris opii, 9j. Misce.

Pain must be relieved by adequate doses of laudanum; and the bowels should be kept open by castor oil, or the infusion of senna with manna.

Mayo's "Observations on Injuries and Diseases of the Rectum," p. 7.

CLASS VIII.

CHRONIC DISEASES OF THE URINARY AND UTERINE SYSTEMS.

CHAP. I.

LITHIASIS.

Objects of Investigation in this Chapter. Depositions from the Urine, primary and secondary. Lithic Diathesis. Circumstances tending to induce or increase it. Depositions of Oxalic Acid and of the Cystic Oxyd. Phosphatic Diathesis. Principles of Treatment in Calculous Affections generally-where the Lithic Diathesis prevails -where the Phosphatic Diathesis prevails. Application of these Pathological views to the determination of questions connected with the operation of Lithotomy.

THE frequency of calculous disorders, and the distress which in their confirmed stages they create, have long made them an object of attention to surgeons; but it is only of late years that the general pathology of these affections (with which the physician is chiefly concerned) has been prosecuted with any degree of scientific precision. Scheele, in 1776, paved the way to a correct understanding of the subject by the discovery of uric acid; but it was reserved for Dr. Wollaston, in 1797, to complete the groundworks of this branch of medical inquiry by his masterly analysis of urinary calculi, published in the Philosophical Transactions of that year. The investigation has been followed up in this country with equal diligence and success; and the writings of Dr. Marcet,* Mr. Brande,† and

An Essay on the Chemical History and Medical Treatment of Calculous Disorders. By Dr. Marcet. Second Edition. 1819.

+ Observations on the Medico-Chemical Treatment of Calculous Disorders. By W. T. Brande. (Quarterly Journal of Science and Arts, vol. viii. and in Phil. Trans. for 1810.)

Dr. Prout,* have put us in possession of a number of important particulars, bearing on the formation and pathology of depositions from the urine, which seem well calculated for discussion in an elementary work. It will be my endeavour, in the present chapter, to lay before the student a brief outline of the opinions of these authors, on the general questions connected with lithiasis.

Character of urinary deposits. - Depositions from the urine are of three kinds :-1. Pulverulent or amorphous sediments. 2. Crystalline sediments, usually denominated sand and gravel. 3. Solid concretions, or calculi formed by the aggregation of these sediments. The same pathological doctrines are applicable to each of these forms of urinary deposition, which obviously can never be understood without a knowledge of the constituent parts of the urine, and of the changes which that fluid undergoes in the body, from agents which either act upon it chemically, or by laws peculiar to vitality. It is this which gives to the consideration of lithiasis an interest so much greater than could have been expected to belong to it. The inquiry, in fact, will be found to have a bearing upon general disease, as much as upon the deranged operations of the urinary organs, and to connect itself intimately with some of the most intricate points in physiology and pathology. It affords a remarkable instance of the application of chemistry to the theory and practice of physic; and though it would be highly unphilosophical to maintain, that the history and treatment of calculous disorders depend entirely on chemical principles, yet it cannot be forgotten, that before this branch of science was cultivated, our notions of lithiasis were vague and incorrect, and that now, the best pathologist, unacquainted with animal chemistry, is continually exposed to the risk of error.

The most general principle which can be taken as the foundation of our reasonings concerning lithiasis is the division of calculous deposites into primary and secondary, or those which take place when the disease first developes itself, and after it has subsisted for a considerable length of time. The primary consist of the lithic acid (either simple, or in combination with ammonia), and of the oxalic acid in union with lime;

An Inquiry into the Nature and Treatment of Gravel, Calculus, &c. By Dr. Prout. London, 1825. Second Edition.

the secondary, of the phosphoric acid combined in various proportions with lime, magnesia, and ammonia. The former derive their chief character from the acid which they contain, the latter from the earthy matters. The first are principally formed in the kidney, the second in the bladder. Hence the distinction into the primary and secondary deposites is nearly equivalent to acid and earthy, renal and vesical; but in the present state of our knowledge all these views of the subject require to be taken with certain limitations, nor do I propose them except as the basis of elementary instruction.

1. Lithic Diathesis.-Under the general denomination of a lithic diathesis, we may arrange, with Dr. Prout, all those states of the system, in which lithic acid is either contained in the urine in more than its natural quantity, or in which the urine acquires a peculiar disposition to deposit it, even though its quantity be not morbidly increased. Such a disposition is given to the urine by a very slight excess of free acid-either the phosphoric, sulphuric, or carbonic. These conditions of the urine may exist independently of each other; but in most instances they are present at the same time, constituting the perfect lithic diathesis. Sediments from the urine, having a lithic character, are usually of a brickdust or pink colour, though this is liable to some variation. They consist of the lithate of ammonia. The crystallized deposites, commonly called red gravel, are lithic acid nearly pure; and many calculi of a large size are composed of the same material.

Several circumstances tend to produce an excess of lithic acid in the urine, and these it will be proper to enumerate.

a. The presence of fever, and of inflammatory action in some part of the system, is always indicated by lateritious or pink sediments of the urine, and the deeper the colour the more severe in general are the symptoms. The latter are especially observed to occur in rheumatic, gouty, and hepatic affections The pathological connection of gout and gravel has long been noticed, and their mutual dependence on predominant acidity in the system was a favourite speculation with many old authors. This theory has certainly received some degree of support from the inquiries of modern pathologists. That excess of lithic acid, however, which is the consequence of fever, can hardly be viewed as a source of the chronic calculous deposites which it is my object now to investigate. I pass on, therefore,

to notice those states of the body independent of fever, which lead to such a result.

B. Of these the most commonly witnessed are simple errors in diet, which may be, either the mere excess of wholesome food; or the partaking of food decidedly unwholesome, or peculiarly difficult of digestion, or such as uniformly disagrees with a particular stomach; or lastly, the indulgence in food at unusual hours. This principle in pathology points out the intimate connection that subsists between gravellish and dyspeptic complaints, to which almost every thing that is important in the treatment of the disease has a reference. It may perhaps be asked, in what manner these derangements of the digestive organs come to increase the formation of lithic acid by the kidney? The question is one of very considerable difficulty. It is not exactly known whether the kidney partakes of the diseased action or not. Dr. Prout is disposed to consider that it does not; and that the mere circumstance of imperfectly assimilated matter being brought in the course of circulation to the kidney, is sufficient to cause the formation of a more than ordinary quantity of lithic acid.

7. Irregularity in exercise, great fatigue, depressing passions of the mind, inordinate mental exertions, all tend in like manner to produce turbid urine from excess of lithic acid. From these remarks it will appear that the tendency to lithic deposition may often be acquired (like gout) by indolent habits and excess in eating and drinking. But there is still another view of the subject which requires to be taken, before it can be appreciated in its several bearings.

8. The disposition in the urine to superabundant lithic acid is sometimes natural, and not unfrequently inherited. Under such circumstances it is usual to see it deposited in the shape of crystalline grains, and there is every reason to believe that these are in most instances formed in the kidney. Such a morbid state of the urine often continues for a great length of time, without occasioning any symptoms of peculiar severity; but sooner or later the constant deposition of crystals of lithic acid in large quantity ends in the formation of a calculus. It is a singular circumstance, that in certain countries and districts of countries, the disposition to lithic deposites from the urine is particularly strong, and calculus therefore is considered as endemic in such situations. A remarkable instance of the kind