Account of a new species of nerium, the leaves of which yield indigo ... To which is added, a brief account of ... experiments made ... to throw ... light on the theory of that artificial reproduction. Also descriptions of two other plants, which yield indigo, and of one from Pegu, said to yield a green dye / [William Roxburgh].

  • Roxburgh, William, 1751-1815.
Date:
[1811]
Catalogue details

Licence: Public Domain Mark

Credit: Account of a new species of nerium, the leaves of which yield indigo ... To which is added, a brief account of ... experiments made ... to throw ... light on the theory of that artificial reproduction. Also descriptions of two other plants, which yield indigo, and of one from Pegu, said to yield a green dye / [William Roxburgh]. Source: Wellcome Collection.

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    soft water i when dry, they proved most beautiful Indigo. No* 1, (hard-water) was considerably the best; but the pro¬ portion of Indigo was in both nearly the same, viz* No. ], gave 241 grains, equal to No, 2. 199 grains, equal to 449 together, or The samples were sent to the Honorable Court of Direc¬ tors by the Europa. I could have wished the quantity had been larger, but the scarcity of the plants, and a desire to preserve most of them for seed, prevented it. I have not yet tried how these leaves are acted on by cold water ; but if we may judge from analogy we may venture to conclude, that It will extract the colour, as well as it does from the leaves of the common Indigo plant. This Indigo did not crack, nor break in drying, but remained perfectly entire, and is of a firm texture, notwithstanding its incom¬ parable levity. January 23, 1793, after a long continuance of dry weather, and strong sea wind, I took seventeen pounds and a half of the leaves of Indigofera cqerulea ; some old, some young, and some of a middle age; scalded them in a twenty gallon earthen pot, in the usual way. (The pot was rather crowded with the seventeen pounds and a half.) As before observed, these leaves require more scalding than those of Nerium. Two thirds of the liquor were taken off, when I judged it at a proper stage j the other third part I suffered to be highly scalded; both were agitated as with Nerium, and as soon as the grain was formed, I added a seventy-fifth part of lime-water. They both precipitated but i 233 1 230