catheter, that will show acid reaction. But this latter circumstance is decisive of the fact that the urine in this case was not secreted ammoniacal, a characteristic and diagnostic feature. Healthy acid urine, continues Dr. Willis, uninoculated by such a ferment, is a fluid that is by no means greatly disposed to run into putrefaction; we often see it withdrawn in cases of retention, after having been pent up in the bladder for two or three days, perfectly unchanged; and I have kept the highly acid urine of a patient labouring under calculus of the kidney in an open vessel for more than a fortnight, in a temperature varying between 50° and 65° F. without its undergoing any change. The ammoniacal urine which is the product of a new combination among the elements of urea at the moment of its formation, is not particularly and otherwise offensive-it has the smell of ammonia superadded to its own urinous odour. That which results from putrefactive decomposision is fetid and disgusting in the last degree.

SECTION 7.-Of the discharge of Urine containing the Hydrocyanic and

Ferrocyanic Acids.

"It has happened in more than one instance in which a salt of iron had either been taken in the way of medicine or accidentally, that the urine voided has presented a blue colour, from containing the compound of ferrocyanic acid and iron which is commonly called prussian blue. Thus Dr. William Batt of Genoa, observed in a girl who had been taking six grains of the æthiops martialis or black oxide of iron daily for a few weeks, on account of some stomach complaints, that the urine evacuated was of a blue colour. The fluid collected and set aside deposited upon the bottom and sides of the recipient a quantity of sediment of a beautiful blue colour. This sediment analysed by Professor Mojon was found to consist of the prussiate of iron. M. Julia Fontanelle has given the histories of two cases in which urine was discharged having a blue colour. The first occurred in the person of an old man aged 82, who, on the second day of an illness caused by an acute affection of the urinary passages, began to pass urine which was thick and ropy, and of a deep blue colour. The ropiness was owing to the presence of a plentiful admixture of albumen or gelatine, the colour to that of the hydrocyanate of iron combined probably with soda. This patient had taken no preparation of iron. But as oxide of iron has been shewn to be a constant constituent of urinary sediments deposited during febrile states of the system, its presence in the colouring compound is readily accounted for. The second case happened in a lad of 15 who was suffering from violent colic, in consequence of having swallowed a quantity of ink by mistake. The urine when first voided was of a greenish blue colour, which after the lapse of an hour deepened into a rich blue. The tint became still more intense (probably from an additional quantity of precipitate being thrown down) when a few drops of the persulphate of iron were added to the urine. The sediment of the urine was found to have all the properties of prussian bluc." 130.

Dr. Willis quotes some other cases to which we need not advert. The urine is generally stated in these cases to have been thick and ropy, and to have contained albumen or gelatine. In one case it contained sugar. In another it shewed traces of urea.

The presence of cyanic acid was only discovered in these cases from its having accidentally met with iron and given rise to a blue colour.

"There is every reason to believe that the cyanic or hydrocyanic acid may often exist in urine, and pass unsuspected. One instance indeed and only one so far as I am aware is recorded, in which prussic acid, free and uncombined, as

I read the various reports of the case, has been detected in the urine. This instance occurred to the distinguished Italian chemist Brugnatelli.* The patient who was the subject of the observation, was affected with dropsy, (an ascites, I believe, from disease of the liver,) and the urine contained almost no urea. M. Cantin's case, free hydrocyanic acid was also ascertained to be present, along with the compound of this acid and iron.

In

There can be little doubt but that the urine, were it properly examined, would be found to contain prussic acid in a variety of morbid conditions of the general system. Hydrocyanic acid is a product of the destructive distillation of animal matters generally, of blood and lithic acid in particular; and we know enough of the chemic powers of the kidney to warrant our admitting its ability upon occasion to separate the elements of the hydrated cyanate of ammonia, or urea, combined as cyanic acid and water, just as they are occasionally eliminated in the shape of bicarbonate of ammonia.

I am not aware that the presence of hydrocyanic acid or of the prussiate of iron in the urine has been attended with any peculiar consequences. Dr. Batt's patient did well. So did both the cases seen by M. Julia. The urine in the cases generally, however, seems to have presented other evidence of being in a morbid state, and in some of them at least, was undoubtedly connected with constitutional derangement, probably with organic lesion, that would have received the most careful consideration from an enlightened pathologist. The albuminous, or as they are sometimes improperly styled, gelatinous states of the urine, point to the existence, in some cases, of inflammatory action in the system, a circumstance which is also farther proclaimed by the plentiful traces of iron encountered, a substance only met with in quantity in the lateritious sediments of inflammatory and febrile urine. These considerations taken in conjunction with every other circumstance would influence, and probably to a certain extent guide, our mode of treating such cases." 133.

SECTION 8. Of the discharge of Urine containing Carbonate of Lime in Solution or as a Deposite.

The carbonate of lime, though it forms an occasional constituent of urinary calculi, has not, to Dr. Willis's knowledge, been observed, either as a solution or a deposit in human urine. Yet he does not doubt that it occasionally exists, though held in solution by an excess of carbonic acid, which also aids in keeping the phosphatic salts dissolved, or disguised from intimate admixture with these and other precipitates, it must always be detected with difficulty.

SECTION 9.-Of the discharge of Urine which is luminous or phosphorescent. -PHOSPHORUria.

The acidifying influence of the kidney on the elements or bases presented to it, may sometimes be imperfectly exerted. The phosphorus in the urine may be in this predicament. Dr. Willis states that there are actually several instances on record, in which the urine has been voided directly from the bladder, either generally luminous, or having luminous points intermingled with it. Thus Dr. Jurine, then in his usual health, whilst making water one dark night in a corner, observed that his urine bore numerous shining

:

"I have searched in vain for a reference to the original record of the case by Brugnatelli. Almost the only place I have not looked into in the hopes of finding its history, is the Journal edited by him, I think at Pisa, in 4 vols. 8vo. 1791-2."

points along with it in its current. The boards down which it flowed, and the leaves upon which it fell, also glimmered with many luminous particles or spots the size of a small lentil. The light continued for about thirty seconds and then disappeared. To make sure that the luminous points he observed were voided with his urine, the Doctor passed a little of it into the palm of his hand, and in this he observed several of them floating about. He closed his hand and hurried home to examine the small quantity of fluid he could carry in this way; but even with the assistance of a magnifier he could discover nothing. Doctor Jurine was living in his usual temperate way when this happened, and though he was on the watch for a recurrence of such a phenomenon, he did not perceive his urine to become phosphorescent for a long time. At the interval of a year, however, the same thing happened again.

Dr. Willis cites, in addition to the preceding, the cases of Dr. Guyton, of Autun-of M. Pictet, of Geneva-of Dr. S. Reisel-and of Dr. L. Pettenkover, all of whom made water very luminously. These enlightened individuals were all men of science, yet Dr. Pettenkover diffidently owns to a tender sentiment towards beer. Dr. Willis asks whether, in those jolly people, who now and then expire of spontaneons combustion, the phosphorus of the body is properly eliminated by the kidney?

SECTION 10. Of the discharge of Urine of various abnormal and

remarkable colours.

The nature of the ordinary colouring matter of the urine is still imperfectly known. Nor is it determined whether the abnormal tints of the urine result from modifications of the colouring matter in question.

"When the colour of abnormally tinted urine depends on the presence of an alkaline purpurate, for a cyanate or phosphate of iron, we conceive the colouring matters developed at the expense, or in consequence of the decomposition, of one or other of the ordinary ingredients of the urine. But instances of red, blue, green, and black urine have occasionally been observed, the peculiar colour of which could not be referred to the existence of any purpurate, or of any combination of iron with the cyanic or phosphoric acid. Of this description appear to have been the varieties of urine observed by many of the ancient physicians, and particularly described by Actuarius, who flourished towards the end of the thirteenth century, in his work De Urinis,' under the titles of Urina venetæ, lividæ et nigræ. The kind of urine characterized as Urina veneta, appears to have been of a slate-gray colour, for the tint designated by the epithet he informs us may be imitated by mixing equal parts of ink and white lead together. The word venetus was afterwards used however to signify a deep blue." 139.

The recent researches, continues Dr. Willis, of Marcet, Prout, and Braconnot have, however, placed it beyond doubt that some deep brown or black, and blue coloured urines owe their peculiar tint to the presence of a new proximate principle, which with reference to a dark brown or black urine was spoken of under the title of Melanie acid by Dr. Prout, and by Braconnot under that of Melanourine. In giving the chemical history of a blue urine, the last-mentioned distinguished chemist speaks of the colouring matter under the name of Cyanourine.

Cases of black urine are rare.

Dr. Marcet has left an account of two. The first was that of a young female subject to febrile and hysterical attacks,

during which the urine assumed a deep purplish brown or black colour. The second case was that of a child seventeen months old, whose urine from the time of his birth had been observed to stain his napkins of a dark purple colour. At nine months of age, the urine was occasionally observed when first discharged to be clear and almost colourless, but gradually to acquire a dark colour like that of port wine, which deepened continually by standing until it became black. At the age of seventeen months, the child was robust and lively. The urine was carefully examined. In one specimen, the deep colour seemed to be due to the action of ammonia, spontaneously evolved, upon a peculiar principle or matter held in solution by the urine. Dr. Prout regarded this as of the nature of an acid, and accordingly named it melanic acid. He found it to bear a closer analogy to lithic acid, or to some of its products engendered by the action of nitric acid, than to any other principle contained in the urine. This specimen of urine remained without further change for a period of seven years, not even depositing any sediment in all that time. A second specimen became alkaline and putrid. A third, colourless at first, became ammoniacal, and acquired a pale claret colour.

"In his account of the chemical examination of some specimens of blue and black urine, M. Braconnot speaks of the colouring principles under the titles of Cyanourine and Melanourine. But, instead of regarding them as of the nature of acids, with Dr. Prout, he found these new proximate principles to have the property of bases, to combine with acids as the weaker alkalis do, and to form compounds, which as subsalts were of a brown, and as supersalts of a brilliant carmine colour. Berzelius remarks, that the melanic acid of Prout is very analogous to the black pulverulent substance, insoluble in alcohol, which is developed when the extractiform constituents of urine are submitted to the action of concentrated acids. The substances named melanic acid and melanourine seem also to bear a strong resemblance to those produced by the action of the hydrochloric acid on fibrine and albumen. If pure fibrine be acted on in this way, the colour of the solution is a rich blue; if it has not been quite pure the tint is of a greenish black, or black." 145.

Dr. Willis refers to two other cases of black urine. In the first, the sweat was black too. In the second, the discoloration of the urine disappeared during the exhibition of the decoction of uva ursi and carbonate of soda.

SECTION 11. Of the discharge of Urine of various peculiar and abnormal

odours.

Several substances, medicinal and dietetic, are well known to impart an odour to the urine-turpentine that of violets-asparagus a disgusting one. Dr. Willis has observed, that the urine of those who have weak digestive powers very constantly partakes in a greater or less degree of the odour of the higher flavoured articles of food they consume. The odour of boiled beef, of stewed celery, of ale and beer, &c. &c., may always be detected in the urine of such individuals.

The smell of the urine, he continues, is also affected to various extents in the course of different diseases. It has sometimes been remarked of a musky odour; occasionally it has the peculiar smell of mice, which seems to pervade the whole body in certain cases of typhoid fever. In other cases it is simply fetid and sickly. He has in particular very frequently observed the urine

to have a most offensive odour in children who were labouring under affections of the digestive apparatus.

Dr. Willis promises to pursue the investigation of this part of the subject, and anticipates something from it.

SECTION 12-Of the discharge of Urine which contains Silica in solution

or as a deposit.

Silica, a sparing ingredient in urine, has been detected in a few urinary calculi. Given to animals, in combination with potash, it finds its way out of the system by the kidney.

"Masses of siliceous matter, said to have been passed from the urinary bladder, are very frequently sent or brought to medical men and chemists for analysis. There are few collections of calculi in which a box of siliceous gravel will not be found. In that of the Royal College of Surgeons in London, for example, I observe one. Dr. Venables believed that he had seen siliceous matter voided by the urine in two instances. In the one, the concretion was of some size, and bore considerable resemblance to a tooth, to which it was likened by Dr. Prout when it was shown to him. In the other, the siliceous matter was like river or sea-sand. Medical practitioners have repeatedly had considerable masses of various mineral substances presented to them as urinary calculi, which they have often been able to pronounce at a glance to be ordinary rolled pebbles of the surrounding country. A friend informed me lately, that within a few weeks he had had, I think, three samples of siliceous urinary gravel transmitted to him for examination, which in each case consisted of pieces of quartz; and I know that both Dr. Bostock and Dr. Christison have oftener than once been requested to ascertain the chemical composition of certain masses of quartz and flint which were said to have been voided from the bladder.

There is every reason to believe that Dr. Venables was imposed upon by his patient, as, in the other instances quoted, imposition was attempted. It has often been remarked, that the so-called siliceous gravel is always of a description in relation within the geological structure of the district in which it is said to have been discharged. Some of the specimens have even had portions of other minerals, with which quartz is known to occur associated, adhering to them. This was the case with at least one of the specimens sent for Dr. Bostock's examination. Patients, and especially female patients, often show a singular taste for having diseases unlike all the rest of the world; and most of the instances in which these siliceous concretions were said to have been voided, occurred in females." 147.

We now arrive at a new chapter and a highly important subject—that of albuminous urine. We have hitherto almost confined ourselves to Dr. Willis. We shall now turn to Rayer and to Christison, particularly to the latter. The chapter of Dr. Willis' before us is intituled :

MORBID STATES IN WHICH CERTAIN MATTERS BEING CONSTITUENTS OF THE BLOOD ARE CONTAINED IN THE URINE.

Dr. Willis starts with the remarks:

"When we observe the rapidity with which fluids in general, and many saline, odorous, and colouring matters taken into the stomach are rendered by the kidneys, when we consider the great vascularity of these organs, and the freedom of communication that must exist between the arterial exhalents and the uriniferous tubules, we are almost prepared to expect that the blood, escaping