Lignum peregrinum aquam caeruleam red-dens C. B. Nephritic wood: an American wood, brought to us in large compact ponderous pieces, without knots: the outer part is of a whitish or pale yellowish colour, the medullary substance of a dark brownish or reddish. It is the product of the Guilandina Moringa of Linnaeus. This wood, macerated in water for half an hour or an hour, imparts a deep tincture, appearing, when placed betwixt the eye and the light, of a golden colour, in other situ-ations of a fine blue: a property in which it agrees with the bark of the ash tree, and differs from all other known woods. Pieces of a different kind of wood, are often mixed with it, which give only a yellow tincture to water.

Nephritic wood has a slightly bitterish some-what pungent taste; and in rasping or scraping emits a faint smell of the aromatic kind. The blue watery tincture has neither smell nor taste: but a strong infusion, which appears not blue, but of a dark brownish colour, is manifestly bitter, and smells pretty agreeably; infpiffated, it leaves a blackish brown extract, in which the bitterness is more considerable, and accompanied with a slight astringency. A saturated tincture made in rectified spirit, is of a blackish red colour; the extract, obtained by infpiffating it, is a tenacious resin, larger in quantity and weaker in taste than the watery extract. According to Cartheufer, the spirituous extract amounts to about one fifth, the watery only to one twelfth the weight of the wood. Both menstrua seem to extract the whole of the active matter; for if the wood remaining after the action of the one, be digested or boiled in the other, and the liquors infpiffated, the extracts thus obtained have neither smell nor taste.

This wood stands greatly recommended in difficulties of urine, nephritic complaints, and all disorders of the kidneys and urinary passages; and is said to have this peculiar advantage, that it does not, like the warmer diuretics, heat or offend the parts: the blue aqueous tincture is directed to be used as common drink, and fresh water to be poured on the remaining wood so long as it communicates any bluness. For my own part, I have never known its being given medicinally, nor is it received in practice: Geoffroy says he has seen some instances of its being used without succefs; and indeed, whatever may be the virtues of strong infusions or extracts of the wood, the exceedingly dilute blue tincture cannot be expected to have much efficacy.