26. A hog-stye has been known to produce violent bilious fevers throughout a whole neighbourhood in Philadelphia.

27. Weeds cut down, and exposed to heat and moisture near a house.

Fevers are less frequently produced by putrid animal, than by putrid vegetable matters. There are, however, instances of their having been generated by the following animal substances in a state of putrefaction.

1. Human bodies that have been left unburied upon a field of battle.

2. Salted beef and pork.

3. Locusts.

4. Raw hides confined in stores, and in the holds of ships.

5. A whale thrown upon the sea shore in Holland.

6. A large bed of oysters. The malignant fevers which prevailed in Alexandria, in Virginia, in 1803, and in Southwark, adjoining Philadelphia, in the year 1805, were derived from this cause[11].