lutely free from danger of contamination, no matter how wisely nor how intelligently the well and cess-pool might be relatively located. We feel that the only way to protect our water wells from fæcal defilement is to keep fæcal matter out of the soil."

SIMPLE TESTS FOR WATER.

It is unfortunate that we have no simple reliable tests for the purity of drinking water. There are certain tests, however, which have a certain amount of value. The following is Hager's test:

"Pour one tablespoonful of a clear solution of tannin (a heaping teaspoonful of tannin to a gill of rain water) into a tumblerful of the suspected water. If no turbidity occurs within five hours, the water is good; if turbidity occurs within one hour, the water is decidedly unwholesome."

Negative results by this test should not be regarded as conclusive, but positive results should lead us to refrain from using the water for drinking purposes. The turbidity depends upon the precipitation of albuminoid matters by the tannin. Heisch's sugar test is as follows:

A four-ounce bottle is thoroughly cleaned and rinsed with the water to be tested, and then filled. About ten grains of pure crystallized cane sugar (rock candy) is added, the stopper inserted, and the bottle placed in a strong light at a temperature of about 80° F. After several hours the water is examined in a good side light with a dark background for any turbidity. The turbidity is due to the growth of a fungus, which Heisch believed to be peculiar to sewage. If examined under a power of 250 diameters it is found to consist of spherical cells, having in most cases a bright nucleus.

Another method is as follows:

To a four-ounce bottle of the suspected water, add 3 ss. of a oneper-cent solution of silver nitrate rendered decidedly alkaline with ammonium hydrate (aqua ammoniæ), and place in a strong light for two hours. Waters containing organic matter turn dark, while those containing little or none show no appreciable tint at the end of two hours. Badly contaminated well waters will show a deep brown to

black color.

Dr. F. De Chaumont gives the following tests, based upon the color produced on heating the residue left on evaporating a portion of the water. The evaporation may be conducted in a saucer, on an ordinary stove. On heating the dry residue to the charring point, it scarcely blackens in pure waters.

In suspicious waters there is much blackening. In bad waters there is much blackening, and nitrous fumes are given off, or there is a smell of burnt horn.

BY JOSHUA M. VAN COTT, JR., M. D.,

Pathologist and Adjunct Professor of Histology and Pathological Anatomy, Long Island College Hospital; Associate Director of the Department of Histology and Pathology, Hoagland Laboratory; Pathologist to the Brooklyn Throat and Nose Hospital.

EXPERIMENTS ON THE ENCYSTING OF FOREIGN BODIES.

Felix Marchand (Ziegler u. Hauwerck's Beiträge zur patholog. Anatomie, Bd. IV., Hft. 1).

The author experimented with pieces of sponge, hardened injected lung, hardened liver, cork, and elder-pith, which he inserted into the peritoneal cavities of animals, principally guinea-pigs.

The results of his numerous experiments regarding the tissue-area in which the bodies were encysted are as follows: Infiltration of leucocytes always formed the commencement of the process. These are both mono- and multinuclear. In the interior of the foreign body the multinuclear cells grow progressively fewer, or are absent altogether. Author believes both varieties of cells to be genetically related-the mono-nuclear being an earlier and the multinuclear a later stage in the life-history of the cells.

The nuclear division, particularly when accompanied with division of cell-protoplasm, he regards as a retrograde metamorphosis, and further says that subdivision of equally active cells ensues only in the direction of mitosis.

A portion of the leucocytes which have gained entrance into the foreign body may again wander out into the lymph-stream; the remainder degenerate inside of it, and probably play an important role in the course of their degeneration in the formation of fibrin in and the fixa tion of the foreign body.

He regards the formation of granulation, or young connective tissue as the work exclusively of pre-existing connective-tissue cells. This formation always commences at the periphery of the tissue, and extends to the point at which the foreign body is bound to the surrounding tissue.

Synchronously with the appearance of young granulation-cells are to be found in the bordering tissues numberless nuclear figures (karyokinesis). The same may be seen in the interior of the foreign body always, and mostly in direct connection with the advancing granulationcells.

The form of the new granulation-cells may be very various; they doubtless possess capacity for contraction and locomotion. The endo

thelial cells appear to take the most active part in forming new cells; but the other tissue-cells also participate in the process. Cell-growth does not begin before the end of the first day.

As is already known, the formation of young blood-vessels proceeds from the older vessels in the surrounding tissues. The infiltration of young cells into the foreign body precedes and is entirely independent of the formation of vessels.

In the giant-cells, which were commonly found in the neighbor. hood of the foreign body, the author could find neither fragmentation nor mitrosis of the nuclei. On the contrary, he believes the giant-cells to be the direct result of fusion of the young new-formed cells. Leucocytes were very commonly found in the giant-cells.

M.'s experiments result in the conclusion that the giant-cells in the foreign body arise from elements in the surrounding tissues, which, in conjunction with leucocytes, coalesce to form multinuclear masses of protoplasm.

SUR LA DIGESTION GASTRIQUE DANS LE COURS DES MALADIES CHRONIQUES DES VOIES RESPIRATORIES.

Chelmouski (Revue de Méd., 1889, No. 7). C. examines the gastric juice of patients suffering with phthisis, emphysema, and chronic bronchitis, all without fever, after the experimental meal of Riegel and the experimental breakfast of Gunzberg, with the following results:

In eleven phthisical patients, reaction of the gastric juice was always acid; in eight of these hydrochloric acid was always absent; in the three others there was an insignificant amount of peptone present. The gastric juice of five of the first, after being sufficiently acidulated, did not digest at all after many days; that of the three others, with hydrochloric acid, not before the lapse of twelve hours. In five of the . eleven patients, digestion was good; two with dyspnoea had, after seven hours, undigested food still in the stomach. The resorptioncapacity of the stomach was insufficient in all of them.

Fifteen patients with emphysema and chronic bronchitis had no hydrochloric acid in their gastric juice. In two of these C. found, after improvement of dyspnoea and bronchitis, a normal gastric juice, while the others behaved in a manner similar to the phthisical patients. C. regards the alteration in the composition of the gastric juice of the phthisical patients as due in part to gastric anæmia, going hand in hand with the general cachexia, partly to endarteritis fibrosa chronica, partly passive hyperæmia, and less often amyloid degeneration of the arteries of the gastric mucosa. In emphysema, chronic passive hyperæmia he regards as the cause of gastric disturbance.

BY RICHMOND LENNOX, M. D.

Assistant Surgeon, Brooklyn Eye and Ear Hospital; Curator and Microscopist, New York Eye and Ear Infirmary.

OCULAR LEPROSY.

Lopez (Knapp's Arch. of Oph., 1889, p. 404), after a brief statement of the chronic nature and parasitic origin of leprosy, gives a very careful enumeration of its effects on the eye and its adnexa. Any part of the eye may be affected, either from a development of the leprous tubercles or (in the case of the external and exposed parts) from mechanical or other injury the result of the leprous anesthesia or the ectropion which so often attends ocular leprosy. As the leprous manifestations generally commence in superficial regions and later invade. the deeper tissues, sight is, as a rule, unaltered until visible lesions have made their appearance. The course of the disease is essentially chronic, and the symptoms of the various ocular manifestations are practically the same as the symptoms of similar conditions due to other causes. In treatment the object must be to avoid, or at most, delay the extension of the disease to the organ of sight, careful protection of the eyes from all mechanical irritants being especially indicated. Ectropion should therefore be promptly corrected, and one need not fear operation, as wounds in lepers heal readily. It seems impossible to arrest the development of a leproma which has invaded the eyeball, but the author believes that cauterization of the tubercle can retard its progress. Locally, antiseptic solutions should be freely used, and such treatment adopted as would ordinarily be indicated in a non-leprous subject. At best we can obtain but improvement, as we have no agent that is to leprosy what mercury is to syphilis.

NERVE TERMINATIONS IN THE CORNEA.

The ordinary descriptions of the terminal nerves of the cornea are that from the more superficial nerve networks in the substantia propria corneæ branches (rami perforantes) pass more or less obliquely outward toward the epithelium to form what is known as the subepithelial plexus, from which again delicate filaments pass between the deeper epithelial cells to form in the superficial layers of epithelium the intraepithelial plexus. From this point opinions vary, some claiming that the nerve fibres terminate by free or club-shaped extremities; others, that they terminate in a network of delicate varicose fibrilla between the epithelial cells, this appearance, however, not extending over a

very large surface. In the substantia propria corneæ it is claimed that the nerves end free, or are connected with the protoplasm of the corneal cells.

Brand (Knapp's Arch. of Oph., 1889, p. 456), in agreement with Goldscheider, who stated in 1886 that all apparent terminations of nerves in epithelium are merely a self-deception, claims that there is no subepithelial or intra-epithelial plexus, but that the so-called ramiperforantes are really the final terminations of the corneal nerves and support the terminal nerve organs. These terminal organs are clubshaped, either single or with two or more horn-like prolongations, and though varying in shape in different individuals or even in the same eye do not rise above the corneal stroma. All of the terminal corpuscles have a sheath-like envelope, the prolongation of the nerve-sheath. Brand has not been able to demonstrate any connection between the nerve fibres in the substantia propria and the corneal corpuscles.

ON THE RECUPERATION OF THE RETINA.

It is a well recognized fact that in common with other parts of the body the retina tires with use. Nevertheless there is but slight difference in the visual power at the beginning and end of a long day's work, and the oculist makes no allowance for the time of day at which his tests for visual acuity are made. This necessary and rapid recuperation of the retina is usually accounted for by the fact that as the retina is constantly receiving new impressions, a constantly changing set of nervous elements is being acted on by the light, and each has, as it were, a chance to rest before its turn for work comes round again. Ocular movements would of course favor this end. At the last meeting of the Heidelberg Ophthal. Society, Fick and Guerter (Bericht u. d. zote Versammlung d. Ophthal. Gesellsh. -Heidelberg) demonstrated however by a number of ingenious experiments, which it would take too much space to detail here, that the ordinarily accepted view is only partially correct, and that the retinal activity is restored by the movements of the eyeballs and of the lids and by the exercise of the accommodation, all acting through the alteration in ocular tension, and therefore in retinal circulation which they produce. As to the exact mechanism of this production, whether by the bringing of fresh nutritive (?) material or the removal of effete matter, no positive statements could be made.

RECURRENT VITREOUS HÆMORRHAGES.

Mayweg (Bericht u. d. 2ote Versamm. d. ophthal. Gesell. Heidelberg) describes a case of this sort in which, after ten relapses, symptoms appeared after which rendered the loss of the right eye imminent, the left having