Culpeper`s complete herbal says:
It is of an opening and cleansing quality, and therefore very effectual for the obstructions of the liver, gall and spleen, and the diseases that arise from them, as the jaundice and hypocondriac; it opens the passages of the urine both in young and old; powerfully cleanses imposthumes and inward ulcers in the urinary passage, and by its drying and temperate quality doth afterwards heal them; for which purpose the decoction of the roots or leaves in white wine, or the leaves chopped as pot-herbs, with a few Alisanders, and boiled in their broth, are very effectual. And whoever is drawing towards a consumption or an evil disposition of the whole body, called Cachexia, by the use hereof for some time together, shall find a wonderful help. It helps also to procure rest and sleep to bodies distempered by the heat of ague fits, or other wise. The distilled water is effectual to drink in pestilential fevers, and to wash the sores.
You see here what virtues this common herb hath, and that is the reason the French and Dutch so often eat them in the Spring; and now if you look a little farther, you may see plainly without a pair of spectacles, that foreign physicians are not so selfish as ours are, but more communicative of the virtues of plants to people.