puscles in a, b, c, fig. 4, were obtained from the living body, while those marked d, e, f, are copies of blood corpuscles taken from Urine. The corpuscles in e and f exhibit characters which are not uncommon.. Their outline is rough, many of them having a stellate character, while some are almost disintegrated.

Some small perfectly circular crystals, which are occasionally present in Urine, may be mistaken for blood corpuscles; but if they be examined carefully, their highly refracting power will be noticed. They are soluble in tolerably strong nitric or hydrochloric acids, which exert but little effect upon the blood corpuscles, further than causing them to shrink somewhat in size. The point, however, can usually be at once decided by examining a few blood corpuscles, and comparing them with the doubtful bodies.

Vaginal epithelium is easily recognized by the large flattened cells which are often folded over at the sides. Each contains a distinct nucleus.

Bladder epithelium varies in character. Many of the cells are columnar, and upon the summits of these, large oval cells are often seen, the under surface of which is marked by numerous depressions, into which the extremities of the cells of columnar epithelium are received. Two or three of these are represented in fig. 6. The columnar epithelium is very abundant near the openings of the

ureters.

PLATE XXI.

VARIOUS DEPOSITS.

Pus. Blood. Triple Phosphate.-The case from which the urinary deposit represented in fig. 1 was derived, was that of a man who had been suffering for many months. from obstinate hæmorrhage from the bladder, accompanied

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with great pain, evidently caused by the presence of fungus growths. The patient gradually sank. Upon post mortem examination, a great number of pendulous growths were found connected with the mucous membrane of the bladder. Pus and phosphates were also almost constantly present. The small bodies, with the sharp well-defined outline, are the blood corpuscles.

Spermatozoa in the mucus from the vagina, in a case of rape. The case will be found described in Number I of the Archives of Medicine.

Casts containing oil and epithelium. Triple phosphate. -The deposit represented in fig. 3 was obtained from a man about 50, who was suffering from phthisis and chronic renal disease, accompanied with oedema of the legs, and slight ascites. The duration of the disease could not be ascertained with any degree of accuracy.

Phosphate of lime.-The amorphous phosphate represented in fig. 2 consists entirely of phosphate of lime. The Urine containing it was slightly alkaline, and the deposit was in it when passed.

Uric acid in the Urine in a case of diabetes.—It has been stated that uric acid was never present in cases of diabetes, and that in this condition hippuric acid took the place of uric acid. This, however, is not true universally. The Urine, in the present instance, deposited much uric acid in the form of large crystals, represented in fig. 5, and contained between 50 and 60 grains of sugar in 1000 of Urine. In this Urine no hippuric acid could be detected. It was sought for according to the method given by Lehmann.

Oxalate of lime, uric acid, penicilium glaucum.-The oxalate of lime crystals in fig. 6 increased in number and size as the fungus was developed. The deposition of the oxalate seemed to be connected with the growth of the fungus. At the same time the uric acid crystals lost their sharpness, and were evidently undergoing solution.

PLATE XXII.

The crystals delineated in all the figures in Plate XXII consist of a peculiar form of phosphate of magnesia, or ammoniaco-magnesian phosphate, but I have never been able to ascertain their exact composition with certainty. I examined some specimens, and found them to be readily soluble in the mineral acids, and they were dissolved slowly by acetic acid. Upon adding excess of ammonia to the acid solution crystals of ammoniaco-magnesian phosphate were precipitated. They were They were not much altered by exposure to a red heat. In figures 3, 4, and 6, various forms approaching the ordinary crystals of triple phosphate may be observed.

These crystals form a white flocculent deposit, which often occupies a considerable bulk. The Urine which contains them is acid, and in many cases a considerable number of crystals of oxalate of lime were also present.

I have found these beautiful crystals in the Urine in so many different cases, that I am led to conclude that their form is determined by other constituents of the Urine, or is dependent upon the rapidity with which they are crystallized. Their presence does not seem to be due to any special morbid condition.

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PLATE XXII.

Fig. 1. Rare form of crystals of triple phosphate and octohedra of oxalate of lime, from the Urine of a girl suffering from icthyosis. Mounted in fluid.

Fig. 2. The same crystals dried and incinerated.

Fig. 3. Two forms of triple phosphate, mounted in Canada balsam.

Fig. 4. Deposit from the Urine of a man suffering from gouty kidney, consisting of a peculiar form of triple phosphate, with granular casts. Given to me by Dr. Johnson.

Fig. 5. Crystals from the same specimen of Urine, as in fig. 1. Crystallized round hairs.

Fig. 6. Forms of triple phosphate and oxalate of lime, from the Urine of a young man enjoying good health, but taking little exercise.