enabling the poet, the philosopher, the politician, the moralist, and the divine, to embody their thoughts for the amusement, instruction, direction and reformation of mankind.—The insect which produces the gall-nut is of the genus Cynips of Linné, but was not known to him or to Fabricius. Olivier first described it under the name of Diplolepis gallæ tinctoriæ[608]. The galls originate on the leaves of a species of oak (Quercus infectoria,) very common throughout Asia Minor, in many parts of which they are collected by the poorer inhabitants and exported from Smyrna, Aleppo, and other ports in the Levant, as well as from the East Indies, whither a part of those collected are now carried. The galls most esteemed are those known in commerce under the name of blue galls, being the produce of the first gathering before the fly has issued from the gall. It will not be uninteresting to you to know, that from these when bruised may occasionally be obtained perfect specimens of the insect, one of which I lately procured in this way. The galls which have escaped the first searches, and from most of which the fly has emerged, are called white galls, and are of a very inferior quality, containing less of the astringent principle than the blue galls in the proportion of two to three[609]. The white and blue galls are usually imported mixed in about equal proportions, and are then called galls in sorts. If no substitute equal to galls as a constituent part of ink has been discovered, the same may be said of these productions as one of the most important of our dyeing materials constantly employed in dyeing black. It is true that this colour may be communicated without galls, but not at once so cheaply and effectually, as is found by their continued large consumption notwithstanding all the improvements in the art of dyeing. Other dyeing drugs are afforded by insects, the principal of which are Chermes, the Scarlet Grain of Poland, Cochineal, Lac-lake, and Lac-dye, all of which are furnished by different species of Coccus.
The first of these, the Coccus Ilicis, found abundantly upon a small species of evergreen oak (Quercus coccifera) common in the south of France, and many other parts of the world, has been employed to impart a blood red or crimson dye to cloth from the earliest ages, and was known to the Phœnicians before the time of Moses under the name of Tola or Thola (ולעת), to the Greeks under that of Coccus (Κοκκος), and to the Arabians and Persians under that of Kermes or Alkermes; whence, as Beckmann has shown, and from the epithet vermiculatum given to it in the middle ages, when it was ascertained to be the produce of a worm, have sprung the Latin coccineus, the French cramoisi and vermeil, and our crimson and vermilion. It was most probably with this substance that the curtains of the tabernacle (Exod. xxvi. &c.) were dyed deep red (which the word scarlet, as our translators have rendered תולעת שני, then implied, not the colour now so called, which was not known in James the First's reign when the Bible was translated)—it was with this that the Grecians and Romans produced their crimson; and from the same source were derived the imperishable reds of the Brussels and other Flemish tapestries. In short, previous to the discovery of cochineal, this was the material universally used for dyeing the most brilliant red then known; and though that production of the New World has, in some respects undeservedly[610], supplanted it in Europe, where it is little attended to except by the peasantry of the provinces in which it is found, it still continues to be employed in a great part of India and Persia[611].
The scarlet grain of Poland (Coccus polonicus) is found on the roots of the perennial knawel (Scleranthus perennis, a scarce plant in this country, but abundant in the neighbourhood of Elvedon in Suffolk), and was at one time collected in large quantities for dyeing red in the Ukraine, Lithuania, &c. But though still employed by the Turks and Armenians for dyeing wool, silk and hair, as well as for staining the nails of women's fingers, it is now rarely used in Europe except by the Polish peasantry. A similar neglect has attended the Coccus found on the roots of Poterium Sanguisorba[612], which was used by the Moors for dyeing silk and wool a rose colour; and the Coccus Uva-ursi, which with alum affords a crimson dye[613].
Cochineal, the Coccus Cacti, is doubtless the most valuable product for which the dyer is indebted to insects, and with the exception perhaps of indigo the most important of dyeing materials. Though the Spaniards found it employed by the natives of Mexico, where alone it is cultivated, on their arrival in that country in 1518, its true nature was not accurately ascertained for nearly two centuries afterwards. Acosta indeed as early as 1530, and Herrara and Hernandez subsequently, had stated it to be an insect. But led apparently by its external appearance, notwithstanding the conjectures of Lister and assertions of Pere Plumier to the contrary, it was believed by Europeans in general to be the seed of a plant, until Hartsoeker in 1694, Leeuwenhoek and De la Hire in 1704, and Geoffroy, ten years later, by dissections and microscopical observations incontrovertibly proved its real origin[614].
This insect, which comes to us in the form of a reddish shrivelled grain covered with a white powder or bloom, feeds on a particular kind of Indian fig, called in Mexico, where alone cochineal is produced in any quantity, Nopal, which has always been supposed to be the Cactus cochinilifer, but according to Humboldt is unquestionably a distinct species, which bears fruit internally white.
Cochineal is chiefly cultivated in the Intendency of Oaxaca; and some plantations contain 50 or 60,000 nopals in lines, each being kept about four feet high for more easy access in collecting the dye. The cultivators prefer the most prickly varieties of the plant, as affording protection to the cochineal from insects; to prevent which from depositing their eggs in the flower or fruit, both are carefully cut off. The greatest quantity, however, of cochineal employed in commerce, is produced in small nopaleries belonging to Indians of extreme poverty, called Nopaleros. They plant their nopaleries in cleared ground on the slopes of mountains or ravines two or three leagues distant from their villages; and when properly cleaned, the plants are in a condition to maintain the cochineal in the third year. As a stock, the proprietor in April or May purchases branches or joints of the Tuna de Castilla, laden with small cochineal insects recently hatched (Semilla). These branches, which may be bought in the market of Oaxaca for about three francs (2s. 6d.) the hundred, are kept for twenty days in the interior of their huts, and then exposed to the open air under a shed, where from their succulency they continue to live for several months. In August and September the mother cochineal insects, now big with young, are placed in nests made of a species of Tillandsia called Paxtle, which are distributed upon the nopals. In about four months the first gathering, yielding twelve for one, may be made, which in the course of the year is succeeded by two more profitable harvests. This period of sowing and harvest refers chiefly to the districts of Sola and Zimatlan. In colder climates the semilla is not placed upon the nopals until October or even December, when it is necessary to shelter the young insects by covering the nopals with rush mats, and the harvests are proportionably later and unproductive. In the immediate vicinity of the town of Oaxaca the Nopaleros feed their cochineal insects in the plains from October to April, and at the beginning of the remaining months, during which it rains in the plains, transport them to their plantations of nopals in the neighbouring mountains, where the weather is more favourable.
Much care is necessary in the tedious operation of gathering the cochineal from the nopals, which is performed with a squirrel or stag's tail by the Indian women, who for this purpose squat down for hours together beside one plant; and notwithstanding the high price of the cochineal, it is to be doubted if the cultivation would be profitable were the value of labour more considerable.
The cochineal insects are killed either by throwing them into boiling water; by exposing them in heaps to the sun; or by placing them in the ovens (Temazealli) used for vapour baths. The last of these methods, which is least in use, preserves the whitish powder on the body of the cochineal, which being thus less subject to the adulterations so often practised by the Indians, bears a higher price both in America and Europe[615].
The quantity at present annually exported from South America is said by Humboldt to be 32,000 arrobas, there worth 500,040l. sterling[616]—a vast amount to arise from so small an insect, and well calculated to show us the absurdity of despising any animals on account of their minuteness. So important is the acquisition of this insect (of which the Spanish government is extremely jealous) regarded, that the Court of Directors of the East India Company have offered a reward of 6000l. to any one who shall introduce it into India, where hitherto the Company have only succeeded in procuring from Brazil the wild kind producing the sylvestre cochineal, which is of very inferior value.
Lac, is the produce of an insect formerly supposed to be a kind of ant or bee[617], but now ascertained to be a species of Coccus, whose history will be adverted to when I come to speak of the secretions of insects; and it is collected from various trees in India, where it is found so abundantly, that, were the consumption ten times greater than it is, it could be readily supplied. This substance is made use of in that country in the manufacture of beads, rings, and other female ornaments. Mixed with sand it forms grind-stones; and added to lamp- or ivory-black, being first dissolved in water with the addition of a little borax, it composes an ink not easily acted upon when dry by damp or water. In this country, where it is distinguished by the names stick-lac when in its native state unseparated from the twigs to which it adheres; seed-lac when separated, pounded, and the greater part of the colouring matter extracted by water; lump-lac when melted and made into cakes; and shell-lac when strained and formed into transparent laminæ;—it has hitherto been chiefly employed in the composition of varnishes, japanned ware, and sealing-wax: but within these few years it has been applied to a still more important purpose, originally suggested by Dr. Roxburgh—that of a substitute for cochineal in dyeing scarlet. The first preparations from it with this view were made in consequence of a hint from Dr. Bancroft, and large quantities of a substance termed lac-lake, consisting of the colouring matter of stick-lac precipitated from an alkaline lixivium by alum, were manufactured at Calcutta and sent to this country, where at first the consumption was so considerable, that in the three years previous to 1810 Dr. Bancroft states that the sales of it at the India House equalled in point of colouring matter half a million of pounds weight of cochineal. More recently, however, a new preparation of lac colour, under the name of lac-dye, has been imported from India, which has been substituted for the lac-lake, and with such advantage, that the East India Company are said to have saved in a few months 14,000l. in the purchase of scarlet cloths dyed with this colour and cochineal conjointly, and without any inferiority in the colour obtained[618].