This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Cabbage. Brassica capitata alba C. B. White cabbage and coleworts. Brassica capitata rubra C. B. Red cabbage. Brassica rubra C. B. Red coleworts. Brassica sabanda: brassica alba capite oblongo non penitus clauso, C. B. Savoy. Brassica cauliflora C. B. Cauliflower. These and the other sorts of cabbages, raised in our culinary gardens, are supposed to be only varieties of the smaller kind, which, in some parts of England, about the sea coasts, is found wild: accordingly they are joined by Linnaeus into one species, under the name of brassica (oleracea) radice caulescente tereti carnosa. They are all biennial.
The several sorts of cabbages are commonly accounted hard of digestion, and of little nourishment, but perhaps not very justly. For as they have manifestly a strong tendency to pu-trefaction, running into this state sooner than almost any other vegetable, and emitting also during the putrefaction a more offensive smell, nearly approaching to the fetor of the animal kingdom; it does not seem irrational to pre-sume, that of all the oleraceous herbs, cabbages may be the mod easily resoluble in the stomach, the moil nutritious, and the least remote from the nature of animal food. Thus much is certain, that they are, in general, not unwhole-some; that they do not induce, or promote, a putrid disposition in the human body, but on the contrary prove a salubrious aliment in the true putrid scurvy*(a); that when taken freely, they tend to loosen the belly and produce flatulencies; and that their laxative matter is ex-tracted by long boiling in water.
Of all these herbs, the white cabbage is the most putrescible; and the red sweetest, and most emollient or laxative. If the stalks of red cabbage, towards the end of autumn, be cut longitudinally and set by for some time in a place not warm, a laxative juice, resembling honey or manna, exudes from the incisions (a). A decoction of this last kind has been greatly recommended in hoarsenesses and some disorders of the breast, for softening acrimonious humours, and promoting expectoration. Boer-haave tells us of very dangerous disorders of the chest cured by the use of a decoction of red cabbage with a little salt and orange juice (b).
*(a) Cabbages cut in slices and packed up in a cask with salt and other additions, ferment, and acquire an acid taste, in which state they are much eaten in Germany under the name of saur kraut. This has lately been introduced as an article of diet in the British navy, and has been found to keep well in long voyages, and to prove a very useful antiscorbutic.