This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Anethum Pharm. Lond. & Edinb. Ane-thum hortense C. B. Anethum graveolens Linn. Dill: an annual umbelliferous plant, with very finely divided leaves and yellow flowers: producing brownish or dark coloured oval seeds, flatted on one side, convex and marked with three longitudinal ridges on the other, and fur-rounded about the edges with a yellowish leafy margin. It is a native of the warmer climates, cultivated with us in gardens, flowers in July, and in September sheds its seeds, by which the plant is plentifully propagated.
(a) Act. nat. curios. dec. ii. ann. 2. p. 120.
The seeds of dill have a moderately warm pungent taste, and an aromatic smell, but not of the mod agreeable kind: they are given as carminatives, to the quantity of a dram at a time, in flatulent colics and indigestion from a laxity of the organs and viscidity of the humours. The leaves are weaker and less grateful than the seeds: the roots have nothing of their flavour.
Water extracts very little of the virtues of dill seeds by infusion or digestion for many hours. In boiling, their whole flavour exhales along with the watery vapour, and may be collected by distillation: the distilled water, drawn off to the quantity of a gallon from a pound of the seeds, is kept in the shops, and occasionally made the basis of carminative draughts and juleps: its flavour is more agreeable than that of the seeds in substance. The simple water keeps better than any in the (hops. A two ounce vial full, corked, after standing on a shelf many years, was clear, without feculence, and retained the flavour of the dill; and might then be looked on as an elegant simple water. Along with the water arises a considerable portion of essential oil, in taste moderately pungent, and smelling strongly of the dill: this is given from one to three or four drops or more, as a carminative, and in hiccups.
Rectified spirit, digested on dill seeds, readily extracts both their smell and taste: the colour of the tincture is a bright yellow: the spirit, gently distilled off from the filtered liquor, brings over very little of its flavour, leaving in the ex-tract nearly all the active parts of the seed.
Aqua anethi Ph. Lond. & Ed.