The essential oil of Valerian lessens the sensibility of the spinal cord after primary stimulation of its nervous substance. A drop of this oil in a spoonful of milk will be a proper dose: especially in some forms of constipation.
Used externally, by friction, the volatile oil of Valerian has proved beneficial as a liniment for paralyzed limbs. The powdered root mixed in snuff is of efficacy for weak eyes.
The cultivated plant is less rich in the volatile oil than the wild herb. On exposure to the air Valerian oil becomes oxidised, and forms valerianic acid, which together with an alcohol, "borneol," constitutes the active medicinal part of the plant.
The root also contains malic, acetic, and formic acids, with a resin, tannin, starch, and mucilage. It is by first arousing and then blunting the reflex nervous activities of the spinal cord, that the oil of Valerian overcomes chronic constipation.
Preparations of Valerian act admirably for the relief of nervous headache associated with flatulence, and in a person of sensitive temperament. They likewise do good for infantine colic, and they diminish the urea; when the urine contains it in excess.
[586] The Greek Valerian is another British species, found growing occasionally in the North of England and in Scotland, being known as the blue Jacob's Ladder. It is also named "Make bate," because said to set a married couple quarrelling if put in their bed. This must be a play on its botanical name Polemonium, from the Greek polemos, war. It is called Jacob's Ladder from its successive pairs of leaflets.
VERBENA.
The Verbena, or Common Vervain, is a very familiar herb on waste ground throughout England, limited to no soil, and growing at the entrance into towns and villages, always within a quarter of a mile of a house, and hence called formerly the Simpler's joy. Of old, much credit for curative virtues attached itself to this plant, though it is without odour, and has no taste other than that of slight astringency. But a reputation clings to the vervain because it used to be held sacred, as "Holy Herb," and was employed in sacrificial rites, being worn also around the neck as an amulet. It was called "Tears of Isis" "Tears of Juno" "Persephonion" and "Demetria." The juice was given as a remedy for the plague. Vervain grew on Calvary: and Gerard says "the devil did reveal it as a secret, and divine medicine."
It is a slender plant with but few leaves, and spikes of small lilac flowers, when wild; but its cultivated varieties, developed by the gardener, are showy plants, remarkable for their brilliant colours.
The name Frogfoot has been applied to the Vervain because its leaf somewhat resembles in outline the foot of that creature. Old writers called the plant Verbinaca and Peristerium:—