wax in its appearance. It dissolved in potash, but was precipitated by excess of acid. It was insoluble in water, alcohol, and ether; but was dissolved by acetic acid, with the aid of heat. In this solution, ferrocyanide of potassium produced a precipitate. It left very little fixed residue after exposure to a red heat.

Blood Calculi.-Dr. Scott Alison furnishes the following interesting remarks with reference to some blood calculi in the kidney ("Archives of Medicine, Vol. I, p. 245). Upon examining the body of a man named William Solly, who was admitted into the Consumption Hospital, Brompton, under the care of Dr. Cursham, on August 23d, and who died on the 30th of the same month, the left kidney was found by Dr. Alison to be greatly wasted and changed in structure. The infundibula and pelvis were stuffed with hard bodies, most of which were of a coalblack color. "The black calculi occupied the pelvis, while the infundibula were tenanted with a few calculi of a whitish-gray color, with one exception small in size, about the magnitude of pear-seeds, and wanting the ordinary physical characters of phosphate of lime. One calculus, which occupied an infundibulum, is the size of a horse-bean, looks somewhat worn and disintegrated, and at one point resembles a piece of decayed wood. At one side it is black, from the presence of altered blood. It is very light in weight, and is composed of blood and phosphate of lime. The black calculi, which form the chief point of interest in the case, were about six in number, and ranged from the size of a coriander-seed to that of a small horse-bean. When found, these black calculi were tolerably hard; but, being friable, they partly broke asunder in handling. The fractured surface varied a little in color, in some parts presenting a dark, rusty tint." Liquor ammonia dissolved these calculi, and they were capable of partial combustion. The microscope revealed only amorphous particles; but Dr. Owen Rees, with the assistance of a neutral saline solution, discovered forms which he considered to be the remains of blood corpuscles. The kidney was remarkably altered. It was very small, but retained somewhat of the normal shape. It weighed

only an ounce and a half, and was only two inches in length. Its color was drab; its consistence was firm and fibrous. At one extremity only could any natural cortical or tubular structure be found. The kidney, in fact, resembled a sac with thin irregular walls. The lining membrane appeared healthy. The renal artery was small, thickened and scarcely admitted a common probe. The ureter was small, but less out of proportion than the artery. The investing membrane could not be separated from the other parts with which it was connected.

The atrophy of the kidney in this case was probably brought about by the production of inflammatory action, set up, perhaps, by the presence of small calculi of phosphate of lime. Blood was probably effused in consequence, and remained in the infundibula and pelvis, failing to be washed down the ureter in consequence of the suppression of the flow of urine. This blood, hardening, would form the calculi which were discovered. After the abatement of the supposed inflammatory action, degenerative processes would supervene and lead to the remarkable atrophy and change which the altered kidney presented. The duties of this wasted organ would be thrown upon the other kidney; but, as the system was much wasted by disease, no increase in size resulted.

"Only a very imperfect history of the patient could be obtained, he being very exhausted when he came into hospital. Since his death, inquiries have been made for information, but with little success. He was fifty-two years old, and by trade a painter. He had been ill with cough two years, and his feet and legs became edematous only two weeks previous to his decease. No information could be obtained respecting his having suffered from calculi in the bladder or from hæmaturia; but it is right to mention that no member of the family of the deceased could be found."

Fatty Concretions.-Specimens of urine which contain large lumps of hard, fatty matter will sometimes be brought for examination. Quite lately I have seen two such specimens, which were said to be cases in which concrete fatty matter had been passed in the urine. In these, however, the fat was ordi

nary suet, as was proved by the presence of the fat vesicle, white and yellow fibrous tissue, and fragments of vessels. Three pieces of suẹt, it was afterwards ascertained, had been introduced by the patient.

CLASS II.-CALCULI WHICH LEAVE A CONSIDERABLE QUANTITY OF FIXED RESIDUE AFTER EXPOSURE TO A RED HEAT.

Oxalate of Lime Calculi.—I have seen an oxalate of lime calculus not larger than the ʊ of an inch, and have traced the formation of such a stone through the several stages of aggregation. I believe that the dumb-bell crystals formed in the kidney, in the first place, become aggregated together, forming small collections, crystalline matter is then deposited in the interstices, and gradually a microscopic calculus results. Microscopic oxalate of lime calculi are represented in Figs. 97, 98, 101, Pl. VIII, " 100 Urinary Deposits."

Microscopic calculi may remain for some time in the kidney, and slowly increase until they form the concretions known as the hemp-seed calculi. Not unfrequently a number of them are formed in the kidney and pass down the ureter one after the other at varying intervals of time. Sometimes one becomes impacted, and gives rise to the most serious and distressing symptoms. Having arrived at the bladder, the slow deposition of the oxalate may continue, or layers of uric acid or phosphate may be deposited, according to the state of the urine.

In cases where the oxalate increases, the surface becomes tuberculated, in consequence of the irregular deposition of the salt; the color varies from a pale brown to a dark brown purple. When these have increased to the size of a nut or larger they are often called mulberry calculi. Such stones often attain a large size. They are very heavy and hard. On section, the laminæ are well seen, and it is often noticed that the calculous matter has been deposited most unequally.

Occasionally the oxalate of lime is deposited almost colorless and crystalline. Dr. Prout figures one of these calculi. I have a beautiful specimen, which was given me by Dr. Gibb, and was obtained from the horse. Large octahedral crystals of oxalate

of lime can be seen all over the surface. The large hemp-seed calculi, which are white on the surface, also exhibit numerous beautiful crystals, although they are smaller than those referred to in the last specimen.

Occasionally, in post-mortem examinations, we are somewhat surprised to find these slowly increasing calculi in the kidney, although the patient never suffered from the slightest symptom during life. I have an oxalate of lime calculus the size of an almond, which I found very firmly fixed in one of the ureters of a man who died of an acute malady. Although its surface is rough, and it is half an inch in diameter, it seems to have caused scarcely any uneasiness, and there was no suspicion of its existence before the patient died.

Mr. McCormick sent me the following history of a case of a large mulberry calculus removed from a patient by Mr. James Ceely, of Aylesbury. It is not a little remarkable that this rough calculus, weighing twelve drachms, should have been present without causing great pain and uneasiness: "At the age of fifteen years the patient (now forty-five) suffered from pain in the hypogastric region, extending along the urethra to the glans penis. At intervals during the succeeding twelve months the pain was very violent, and was at each attack followed by the evacuation of bloody urine. Occasionally since then he experienced pain in these situations, while taking horse exercise, or during unusual exertion, but never to any great extent, and he was never compelled to seek advice. With these exceptions his general health, although delicate, had been good until June (1858), when he had an accession of symptoms resembling those mentioned, but greatly aggravated. The urine, in addition to blood, contained gravel.' At this time he consulted Mr. Reynolds, of Thame, who detected a vesical calculus, and on the 20th September, Mr. J. H. Ceely performed the lateral operation and removed a rough, irregular, mulberry calculus, weighing twelve drachms, During the first ten days subsequent to the operation, the urine contained considerable quantities of pus and blood, after which time all abnormal characters disappeared, and the patient was discharged from the Bucks Infirmary, perfectly

well, on the 8th of October, and had suffered little pain or inconvenience. This patient had enjoyed excellent general health during a period of twenty-nine years, notwithstanding the presence of a calculus probably during the whole period."

A calculus of very curious shape, the nucleus of which consisted of oxalate of lime, is described by Mr. Price in the eleventh volume of the "Transactions of the Pathological Society." Mr. Price removed fourteen calculi from the bladder of an old man, by the lateral operation of lithotomy. Two of the calculi were peculiar in possessing several spine-like projections. The largest of these was about the size of a chestnut, and from its surface projected from eight to ten spines, two of which were upward of half an inch in length. Surrounding the oxalate of lime nucleus were several layers of uric acid and urates, with some earthy phosphate. The spines were formed of the latter salts alone, and there was no projection of the oxalate of lime nucleus into them. The cause of their peculiar shape could not be ascertained. The stone was not in any pouch in the bladder, but was free in its cavity, and the absence of any spines projecting from the nucleus militates against the idea of the peculiar form having been given to it while in the kidney. No post-mortem was allowed. It seems possible that the formation of the spines might have depended upon the more rapid deposition of calculous matter on those parts opposite to the intervals between the smaller calculi, than over the part of the surface in immediate contact with them, as only the two largest calculi exhibited this peculiarity.

Calculi in Patients who have had Cholera.--The circumstances under which oxalate of lime is deposited in the form of the dumb-bell crystals have already been alluded to. It is interesting to find that both Drs. Prout and Kletzinsky have noticed deposits of oxalate of lime in patients who had had cholera, in which disease the fluids are in a high state of concentration. two cases of this disease dumb-bells of oxalate of lime were found in the urine by myself. Dr. Prout also alludes to the frequency of cases of calculous disease in those who had suffered from cholera. These are importants facts in favor of the view I en

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