Milfoil, or yarrow is a perennial herb, very common both in Europe and America. It is from a foot to eighteen inches in height, and is specifically distinguished by its doubly pinnate, downy, minutely divided leaves, with linear, dentate, mucronate divisions, from which it derived the name of milfoil, by its furrowed stem and involucre, and by its dense corymbs of whitish flowers, which appear throughout the summer, from June to September. Achillea nobilis, L., and A. moschata Jacq., or Iva of Europe, are sometimes used as substitutes for A. Millefolium.

Both the flowers and leaves of A. Millefolium have an agreeable, though feeble, aromatic odor, which continues after drying, and a bitterish, astringent, pungent taste. The aromatic properties are strongest in the flowers, the astringency in the leaves. The plant contains volatile oil, tannin, and a peculiar principle, achillein, which was discovered by Zanon. (Ann. Ch. Ph., Iviii, 21.) As analyzed by von Planta (Ann. Ch. Ph., Helv, 1870) its formula is C₂₀H₃₈N₂O₁₅. It occurs in a brownish-red mass of a strongly bitter taste, soluble in water, more feebly in alcohol, and not at all in ether. Achilleic acid, also discovered by Zanon, is affirmed by Hlasiwetz to be identical with aconitic acid. The oil, which may be obtained separately by distillation with water, has a beautiful azure-blue color, and the peculiar flavor of milfoil. Schimmel & Co. (B. Chem. G., 1894, p. 50) found its most important constituent to be cineol. The high boiling blue portion is probably identical with the azulein of chamomile oil. Ivain, C₂₄H₄₂O₅, has also been isolated; it occurs as a dark-yellow resinous mass, insoluble in water, readily soluble in alcohol, and producing an intensely bitter solution. There are a number of other species of achillea which have been distilled for the volatile oil, including A. coronopifolia Willd., A. moschata Jacq., A. nobilis, and A. ageratum L.

The oils from these plants, while showing certain resemblances, vary greatly in physical properties. The specific gravity of the volatile oil has been variously reported as from 0.869 to 0.927. Milfoil is a mild aromatic sudorific tonic and divided doses up to from thirty to seventy-five astringent. Pappi states that achillein given in grains (2-5 Gm.) causes marked irregularity of the pulse. The infusion is sometimes used in acute suppression of the menses.

Habitat. Yarrow grows everywhere, in the grass, in meadows, pastures, and by the roadside. As it creeps greatly by its roots and multiplies by seeds it becomes a troublesome weed in gardens, into which it is seldom admitted in this country, though it is cultivated in the gardens of Madeira The name Yarrow is a corruption of the Anglo-Saxon name for the plant - gearwe; the Dutch, yerw.

Description. The stem is angular and rough, the leaves alternate, 3 to 4 inches long and 1 inch broad, clasping the stem at the base, bipinnatifid, the segments very finely cut, giving the leaves a feathery appearance. It flowers from June to September, the flowers, white or pale lilac, being like minute daisies, in flattened, terminal, loose heads, or cymes. The whole plant is more or less hairy, with white, silky appressed hairs.

Yarrow was formerly much esteemed as a vulnerary, and its old names of Soldier's Wound Wort and Knight's Milfoil testify to this. The Highlanders still make an ointment from it, which they apply to wounds, and Milfoil tea is held in much repute in the Orkneys for dispelling melancholy. Gerard tells us it is the same plant with which Achilles stanched the bleeding wounds of his soldiers, hence the name of the genus, Achillea. Others say that it was discovered by a certain Achilles, Chiron's disciple. It was called by the Ancients, the Herba Militaris, the military herb.

Its specific name, millefolium, is derived from the many segments of its foliage, hence also its popular name, Milfoil and Thousand Weed. Another popular name for it is Nosebleed, from its property of stanching bleeding of the nose, though another reason given for this name is that the leaf, being rolled up and applied to the nostrils, causes a bleeding from the nose, more or less copious, which will thus afford relief to headache. Parkinson tells us that 'if it be put into the nose, assuredly it will stay the bleeding of it' � so it seems to act either way.

It was one of the herbs dedicated to the Evil One, in earlier days, being sometimes known as Devil's Nettle, Devil's Plaything, Bad Man's Plaything, and was used for divination in spells. Yarrow, in the eastern counties, is termed Yarroway, and there is a curious mode of divination with its serrated leaf, with which the inside of the nose is tickled while the following lines are spoken. If the operation causes the nose to bleed, it is a certain omen of success:

An ounce of Yarrow sewed up in flannel and placed under the pillow before going to bed, having repeated the following words, brought a vision of the future husband or wife:

It has been employed as snuff) and is also called Old Man's Pepper, on account of the pungency of its foliage. Both flowers and leaves have a bitterish, astringent, pungent taste. In the seventeenth century it was an ingredient of salads.

Parts Used. The whole plant, stems, leaves and flowers, collected in the wild state, in August, when in flower.

Constituents. A dark green, volatile oil, a peculiar principle, achillein, and achilleic acid, which is said to be identical with aconitic acid, also resin, tannin, gum and earthy ash, consisting of nitrates, phosphates and chlorides of potash and lime.

Medicinal Action and Uses. Diaphoretic, astringent, tonic, stimulant and mild aromatic.

Yarrow Tea is a good remedy for severe colds, being most useful in the commencement of fevers, and in cases of obstructed perspiration. The infusion is made with 1 oz. of dried herb to 1 pint of boiling water, drunk warm, in wineglassful doses. It may be sweetened with sugar, honey or treacle, adding a little Cayenne Pepper, and to each dose, a teaspoonful of Composition Essence. It opens the pores freely and purifies the blood, and is recommended in the early stages of children's colds, and in measles and other eruptive diseases.

A decoction of the whole plant is employed for bleeding piles, and is good for kidney disorders. It has the reputation also of being a preventative of baldness, if the head be washed with it.

Preparations. Fluid extract, �to 1 drachm. An ointment made by the Highlanders of Scotland of the fresh herb is good for piles, and is also considered good against the scab in sheep. An essential oil has been extracted from the flowers, but is not now used.

Linnaeus recommended the bruised herb, fresh, as an excellent vulnerary and styptic. It is employed in Norway for the cure of rheumatism, and the fresh leaves chewed are said to cure toothache. In Sweden it is called 'Field Hop* and has been used in the manufacture of beer. Linnaeus considered beer thus brewed more intoxicating than when hops were used. It is said to have a similar use in Africa. Culpepper spoke of Yarrow as a profitable herb in cramps, and Parkinson recommends a decoction to be drunk warm for ague.

Head. � Vertigo when moving slowly. Sensation as if he had forgotten something. The head seems full of blood. Convulsions and epilepsy from suppressed menses. Piercing thrusts of pain.

Nose. � Nosebleed, [Erecht.] Piercing pain from eyes to root of nose.

Stool. � Hemorrhage from bowels. Bleeding haemorrhoids. Urine bloody. [Senec. aur.]

Female. � Menses early, profuse, protracted. Haemorrhage from uterus; bright red, fluid. Painful varices during pregnancy.

Respiratory. � Haemoptysis in incipient phthisis. Cough, with bloody expectoration, in suppressed menses or haemorrhoids. Violent palpitation.

Relationship. � Compare: Ficus venosa (Pakur). Haemorrhage from bowels and lungs. Acalypha and Helix tosta � Snail � (in haemoptysis, diseases of chest, consumption); also, Secale; Ipec.; Erecht.; Geran.; Hamam.

Dose.� Tincture, to third potency.