A drop of old tuberculin, which is an extract of tubercle bacilli, is put on the skin and then a small superficial scarification is made by turning, with some pressure, a vaccination lancet on the surface of the skin. The next day only those individuals show an inflammatory reaction at the point of vaccination who have already been infected with tuberculosis, whereas the healthy individuals show no reaction at all. Every time we find a positive reaction, we can say with certainty that the child is tuberculous.

If a Schirrus by long standing, increasing, and motion of the adjacent Parts is thus moved, that the neighbouring Vessels around its edges begin to inflame, it’s become malignant, and from its likeness to a Crab, is now called a Cancer, or Carcinoma.

The autopsy of a person who had died from phosphorus poisoning would reveal inflammation and haemorrhage in the stomach and bowel, the liver would show fatty changes and both it, and the kidneys would be enlarged, greasy and of a yellow colour. But the most convincing proof of death due to phosphorus exposure would be to turn off all the lights in the mortuary and see its tell-tale glow...

The physical signs of measles are nearly the same as those of smallpox, but nausea and inflammation is more severe, though the pains in the back are less.

The signs of liver inflammation [hepatitis] are eight in number, as follows: high fever, thirst, complete anorexia, a tongue which is initially red and then turns black, biliary vomitus initially yellow egg yolk in color, which later turns dark green, pain on the right side which ascends up to the clavicle. … Occasionally a mild cough may occur and a sensation of heaviness which is first felt on the right side and then spreads widely.

There are, I believe, very few maxims in philosophy that have laid firmer hold upon the mind, than that air, meaning atmospherical air (free from various foreign matters, which were always supposed to be dissolved, and intermixed with it) is a simple elementary substance, indestructible, and unalterable, at least as much so as water is supposed to be. In the course of my enquiries, I was, however, soon satisfied that atmospherical air is not an unalterable thing; for that the phlogiston with which it becomes loaded from bodies burning in it, and animals breathing it, and various other chemical processes, so far alters and depraves it, as to render it altogether unfit for inflammation, respiration, and other purposes to which it is subservient; and I had discovered that agitation in water, the process of vegetation, and probably other natural processes, by taking out the superfluous phlogiston, restore it to its original purity.

To choose a rough example, think of a thorn which has stuck in a finger and produces an inflammation and suppuration. Should the thorn be discharged with the pus, then the finger of another individual may be pricked with it, and the disease may be produced a second time. In this case it would not be the disease, not even its product, that would be transmitted by the thorn, but rather the stimulus which engendered it. Now supposing that the thorn is capable of multiplying in the sick body, or that every smallest part may again become a thorn, then one would be able to excite the same disease, inflammation and suppuration, in other individuals by transmitting any of its smallest parts. The disease is not the parasite but the thorn. Diseases resemble one another, because their causes resemble each other. The contagion in our sense is therefore not the germ or seed of the disease, but rather the cause of the disease. For example, the egg of a taenia is not the product of a worm disease even though the worm disease may have been the cause, which first gave rise to the taenia in the intestinal contents—nor of the individual afflicted with the worm disease, but rather of the parasitic body, which, no matter how it may have come into the world at first, now reproduces itself by means of eggs, and produces the symptoms of the worm disease, at least in part. It is not the seed of the disease; the latter multiplies in the sick organism, and is again excreted at the end of the disease.