artificially tuberculised are quite correct; (4) That material other than tuberculous does not produce tuberculosis, that is to say, that the cases of artificial tuberculosis in guinea-pigs observed by Wilson Fox and Burdon Sanderson, and in the older experiments of Cohnheim and Fraenkel, viz. those in which chronic inflammation and caseation (i.e. artificial tuberculosis) was thought to have been induced by other than tuberculous matter, e.g. by non-tuberculous caseous matter, setons, indifferent substances like bits of gutta-percha inserted into the peritoneal cavity, &c., were really due to accidental contamination with tuberculous material.

According to my own experience extending over a very large number of cases of human miliary tuberculosis and tuberculosis of cattle, I cannot for a moment accept the statement that the bacilli found in the two affections are identical; for I find that in the two diseases their morphological characters and distribution are very different. The bacilli of human tuberculosis are conspicuously larger than those of the tuberculosis of cattle, and in many instances more regularly granular. As is seen in Figs. 83-85, those of human sputum are nearly half, or at least one-third, as large again as those of the caseous masses from the lungs of cattle.

The bacilli in the tuberculous deposits of cattle are always contained in the cells; the larger the cell the more numerous the bacilli. This fact comes out very strikingly in thin and well-stained sections. Around many of the smaller and larger clumps of bacilli the cell-outline is still recognisable, and when the cell disintegrates, as it does sooner or later, the bacilli become free in groups; in this respect there exists a remarkable similarity between leprosy and bovine tuberculosis. But in the human tubercles the bacilli are always scattered between the cells.

I cannot agree with Koch, Watson Cheyne, and others, who maintain that each tubercle owes its origin to the immigration of the bacilli, for there is no difficulty in ascertaining that in human tuberculosis, in tuberculosis of cattle, and in artificially induced tuberculosis of guinea-pigs and rabbits, there are met with tubercles in various stages-young and adult-in which no trace of a bacillus is to be found; whereas in the same section cheesy tubercles may be present containing numbers of tubercle-bacilli.

Schuchardt and Krause1 have found tubercle-bacilli, though

I Fortschritte d. Med. 9, 1883.

sparingly, in fungoid and scrofulous inflammations; Demme 1 and Doutrelepont 2 found the tubercle-bacilli also in the tissue of lupus. But the bacilli occurring in the lupus-tissue, as far as I am able to see, are morphologically different from the tubercle-bacilli. In a preparation made of the juice of lupus

FIG. 87.-FROM A SECTION THROUGH THE KIDNEY OF RABBIT DEAD OF ARTIFICIAL TUBERCULOSIS.

a. Blood-vessel filled with caseous matter, and in it numerous tubercle-bacilli. b. Nuclei of cells of the tuberculous new growth.

c. Capillary vessel in cross section.

Magnifying power 700.

tissue, large transparent cells with several nuclei are found, in the cell substance of which are noticed groups of thickish, short bacilli, thicker and shorter than tubercle-bacilli. bacilli are either placed singly or in chains of two.

These

The so-called Bacillus of Cholera.-In the reports from India by Dr. Koch, as the head of the German Commission sent to investigate the recent outbreak of cholera in Egypt, we notice that, like the French Commission, they failed to communicate the disease to animals; that the German Commission failed to discover any specific organism in the blood of patients suffering from cholera ; that the intestines contained in their cavity and wall numerous peculiar "comina-shaped" bacilli, which Koch considers to have a special relation to

1 Berliner klin. Woch 15, 1883.

2 Monatshefte f. practische Dermatologie, 6, 1883.

FIG. 88.-FROM THE SAME KIDNEY AS IN PRECEDING FIGURE.

a. Large artery filled with caseous matter, and in it numerous tubercle-bacilli. b. Coat of artery.

c. Nuclei of the tuberculous new growth

d. A Malpighian corpuscle.

FIG 89.-FROM THE JUICE OF LUPUS-TISSUE PREPARED AFTER THE KOCH. WEIGERT METHOD OF DRYING A THIN LAYER ON A COVER-GLA: S. Magnifying power about 700.

the disease. Considering the state of the intestine in this disease, the presence of the bacilli, however peculiar, in its wall is in itself not convincing proof of their specific nature. Considering also that animals are as yet found insusceptible to cholera, artificial cultivations of these bacilli, successfully accomplished by Koch, cannot be tested.

From the artificial cultivations of these comma-shaped bacilli, Koch learned that it is necessary that the nourishing medium should have an alkaline reaction, and that the bacilli are easily killed by drying. Koch found these comma-shaped bacilli in linen soiled with the cholera dejecta, also in the water of a tank that had produced cholera in several people who had partaken of it. As soon as the bacilli disappeared from this water cholera cases ceased.

My friend Mr. A. Lingard has placed at my disposal sections through the human intestine from cases of dysentery; there are seen in the superficial parts of the necrosed mucous membrane large numbers of putrefactive bacilli. In

FIG. 90.-FROM A SECTION THROUGH THE MUCOUS MEMBRANE OF THE INTESTINE OF A PATIENT DEAD OF DYSENTERY.

A number of blood discs (extravasated into the tissue of the mucous membrane) and between them long thin bacilli. Magnifying power 700. (Stained with methyl-blue.

some cases, however, in the depth of the tissue there are found, amongst the extravasated blood-corpuscles, numbers of very fine, long, straight, or more commonly curved, bacilli and bacillus filaments; some are distinctly made up of a chain of long bacilli. They stain well and conspicuously in methylblue.

CHAPTER XII.

VIBRIO.

VIBRIONES are characterised by being rod-shaped, but not straight; they are more or less wavy; and they are motile. (a) Vibrio rugula consist of rods of about 0.008 to 0.016 min. in length, and curved either like a Cor like an S. They

are single, or form chains of two. Their protoplasm is always slightly granular. They are found in putrefying organic substances, and often form continuous masses, the individuals interlacing in all directions.

K