Five letters to Sir Joseph Banks ... on the subject of cochineal insects, discovered at Madras / [James Anderson].

  • James Anderson
Date:
1787
Catalogue details

Licence: Public Domain Mark

Credit: Five letters to Sir Joseph Banks ... on the subject of cochineal insects, discovered at Madras / [James Anderson]. Source: Wellcome Collection.

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    ** makes little or no imprefiion on paper, while the Spanifh gives a red “ Ink colour, both tinctures were equally dilute and fo far unfit for Ink ; “ another circumftance remarkable is the difference in drynefs of the two “ Cochineals, owing oartly perhaps to the mo^le of drying partly to age, “ the Spanifh was cafily reduced to powder, the Madras by trituration was “ turned into pallc.” In addition to what Doffor Ruffcll has faid, I muff obferve, the frefli gathered Infefts yeild a brighter colour as after roafting to kill the young they acquire a confiderably darker hue, the want of whitenefs on the out- fu’e, is owing to the uiky Ihell being caretully picked off, whether this trouble is proper or nor, 1 am yet at a lofs to determine, but even the pro- per ikin of the Aurelia is of a ciokr texture as he very judly obferves is more fplendent, and when thrown into water without previous trituration gives out none of Its colour, w hereas the criterion amonfi; ivlerchants of genuine Cochineal, is the darting of red rays, from it even to the bottom of a glafs of vvater foun after immerfion •, perhaps this quality is what preferves our Inltft from total deftrudtion, during the Monfeon •, I obferve too that on feme grafs, cultivated lo as to grow more luxuriant, the Inlcdts have been found ccnfiJerably larger than on the waRe lands* The Specimen he uff’ci had been expofed to the Sun every day for two nior.tbs, vvhen the Therotometer in the Shade was about 78° yet it could not be reduced to a powder, ow-ing to fat with which it abounds; and I th r k, flinlds it t'om the .-btion of acid Saks — Yet it readily communicates a Pompadour or dee[) bed col >ur to woolen and animal matters, when ufed in the quantity Defter L.ewis in his notes to the Tranflinon of Newmans ChemeRry, fays he found nectffary of the Silvefter Cochineal, and a deceftjon made in lime water becomes Purple,.which colour it in lomc degree imparts to Linnen.and.Cotioa. By means of a friend, Captain Doveton, I have traced the exiftence of the grafs Cochineal all the way from this place to Vizagapatam, and although I have not been able to find it on any plant befides the grafs nientioned in my. firR letter, and on that only in its chryfalis Rate, when the whitnefs of its filky envelope renders it confpicuous, yet it appears to me any qu.inrirv, rhat could be brought inro ufe may be collefted, as the fields from whence 1 have had every Inlcft brought-that could be found are again as plentifully Rock’d in five or fix weeks arter, as ever ; and i.i ad probanility they may be found every day in the year except the month of Qftober, when the country is covered with water. The expence of collefting and curing them I fuppofe could not be under five or fix fhil'ings a pound, fo they could not be brought to maikvt in Huiope at a lower race than half a guinea the pound, witn lefpeft to colour toot f
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