5. _Diarrhoea calida._ Warm diarrhoea. This species may be divided into three varieties deduced from their remote causes, under the names of diarrhoea febrilis, diarrhoea crapulosa, and diarrhoea infantum. The febrile diarrhoea appears at the end of fever-fits, and is erroneously called critical, like the copious urine, and the sweats; whereas it arises from the increased action of those secerning organs, which pour their fluids into the intestinal canal (as the liver, pancreas, and mucous glands), continuing longer than the increased action of the intestinal absorbents. In this diarrhoea there is no appearance of curdled chyle in the stools, as occurs in cholera. I. 3. 1. 5.
The _diarrhoea crapulosa_, or diarrhoea from indigestion, occurs when too great a quantity of food or liquid has been taken; which not being compleatly digested, stimulates the intestines like any other extraneous acrid material; and thus produces an increase of the secretions into them of mucus, pancreatic juice, and bile. When the contents of the bowels are still more stimulant, as when drastic purges, or very putrescent diet, have been taken, a cholera is induced. See Sect. XXIX. 4.
The _diarrhoea infantum_, or diarrhoea of infants, is generally owing to too great acidity in their bowels. Milk is found curdled in the stomachs of all animals, old as well as young, and even of carnivorous ones, as of hawks. (Spallanzani.) And it is the gastric juice of the calf, which is employed to curdle milk in the process of making cheese. Milk is the natural food for children, and must curdle in their stomachs previous to digestion; and as this curdling of the milk destroys a part of the acid juices of the stomach, there is no reason for discontinuing the use of it, though it is occasionally ejected in a curdled state. A child of a week old, which had been taken from the breast of its dying mother, and had by some uncommon error been suffered to take no food but water-gruel, became sick and griped in twenty-four hours, and was convulsed on the second day, and died on the third! When all young quadrupeds, as well as children, have this natural food of milk prepared for them, the analogy is so strong in favour of its salubrity, that a person should have powerful testimony indeed of its disagreeing, before he advises the discontinuance of the use of it to young children in health, and much more so in sickness. The farmers lose many of their calves, which are brought up by gruel, or gruel and old milk; and among the poor children of Derby, who are thus fed, hundreds are starved into the scrophula, and either perish, or live in a state of wretched debility.