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bear certain proportions to each other.. Now if any particular species exceed those proportions, it will, in a greater or less degree, become obnoxious, and in degree disturb the requisite balance. Under such circumstances, it becomes necessary that such superabundance should be checked; we therefore see, throughout the entire system of animated nature, that all this is provided for by one creature preying upon another-" some few are sacrificed to the good of the whole."
Now, if we look into the history of insects we find a most important part played by them in the great scheme of Nature; there is scarcely a single plant that has not its appointed insect-frequently many that live upon the same plant. Now, when we cultivate particular plants until we mature them into the edible vegetables we enjoy, we must not be surprised if we find some of these insects attacking our produce : it then becomes our appointed business to exert our faculties, and to invent means of guarding against such attacks; and who can estimate the benefit that may arise from the very circumstance of our faculties having been so sharpened? It is under these circumstances that some of the most important discoveries are often made.
Who can doubt that it is a wise provision that races of insects should exist whose mission is to remove superabundant vegetation? Not that I mean superfluous production, but a production that, having performed its appointed end, requires removal, and that removal is to be through the agency of insects. You have all read some account of the visitation and devastation of locusts, and of the destruction occasioned by their countless myriads. You must understand that these visitations only take place at intervals. There is a locust, common in the United States, which appears at regular intervals of seventeen years; so that in some districts next year is now looked forward to as a locust year. But, as I have already observed, we must look, not to individual or to local losses, but to general benefits. In some regions of the globe such is the profuse exuberance of vegetable life, that a visitation of locusts clears whole districts that had become choked up through this teeming production; and we are told by residents in such districts, that the removal of this superabundance is frequently followed by the growth of new herbs, luxuriant and fresh grasses, suited as pasture for the wild cattle that inhabit such localities.
And thus it is we see the interest of individual man sacrificed for the general good; and insects which he regards as so many pests will often be found most beneficial to him. Insects that feed upon the roots of grass, such as the larva of the common cockchafer, which does
so during a space of nearly four years, removes those grasses that are become coarse; and so by these means room is made for fresh young shoots, which renders the pastures more nutritious to the cattle that graze upon them. The earth-worm also plays a most important part in our fields, turning up the earth, and opening passages for air and moisture.
But I will now proceed to notice a few insects, the use of which will be apparent to every one; and probably the insect which creates the ink-gall is as good an instance as can be selected. The ink-gall of commerce is not found in this country; it is the production of a species of cynips, called Cynips Galle tinctoria. It is an exceedingly common insect in Southern Europe; the galls are collected in enormous quantities from oak-trees, and are an important article of commerce throughout Europe. From these galls the best kinds of ink have been manufactured for many years. Thousands of pounds' worth of these galls are imported into this country every year, and no discovery in chemistry has produced any article from which ink can be manufactured equal to that made from the gall of this little cynips.
Another most direct benefit which man derives from insects is the use, in medical science, of the blister-fly or blister-beetle, Cantharis vesicatoria. This valuable insect is principally imported from Spain; it is occasionally found in this country, but is of rare occurrence; in many parts of Europe it is found in immense numbers. Now the very profusion of this insect is to be regarded as a beneficent provision. Who can even imagine the benefit man has derived from the use of blisters prepared from these insects? in how many million of cases has relief been afforded-in how many even life itself preserved? I must remind you, that in tropical countries each one seems to be provided with insects equally beneficial as Cantharis vesicatoria: in India several species are used; China has several, and the Brazils and South America are supplied with other species equally beneficial.
I am now going to allude to useful insects which every one will admit to be so, and none more readily than the ladies; I am about to speak of the producers of silk. It would almost appear to us, in the present day, that silk-producing insects are a positive necessary; and although such is not the case, strictly speaking, still we all readily admit silk to be one of the most splendid productions in nature. Silk is the product of an insect of foreign origin; and we are not, in estimating its value, to consider it merely in so far as it contributes to the comforts, necessities, or to the luxury of Europeans. We know well
that it might have been possible to obtain materials for clothing from the wool of our flocks, and from the flax grown in our fields; but we are to look at it in other aspects, we are to consider necessities as they contribute to the universal good. Wool and flax we produce in this country; America has hitherto been the great emporium of cotton; and China and India the great silk-producing countries. Now, in the latter how many individuals obtain their living entirely from the cultivation of silk? There are those employed in planting, and attending to the great plantations of the mulberry-tree; those who collect the cocoons of the silk-producing moths, the Bombyx mori; the replacing of the moths upon the trees after the silk has been spun off; then there are those who prepare the raw material for the loom, for the purpose of home manufacture; then of that which is intended for the foreign market. It has been estimated that in China alone the silkworm-moth furnishes a livelihood for from two to three millions of individuals. We instantly appreciate the use of Bombyx mori when we have so estimated its value. But we must not forget that thousands are now employed in southern Europe in the cultivation of the silkworm. And let us not forget that after the silk is imported into Europe how many thousands obtain their living in the manufacture of it.
It appears that silk has been manufactured in China from the most ancient times; the oldest records speak of it as a common article of of dress; and yet it was not known in this country previous to the time of Queen Elizabeth; its use and manufacture are now almost universal in civilized countries-modern science has discovered several moths, producers of silk, some little inferior to that of the Chinese Bombyx mori. It has been supposed possible to cultivate silk in this country, and the attempt has been made, and small quantities of silk have been manufactured; but the climate is not adapted to the insects, and the cost of production, even in the most favourable seasons, effectually debars its ever becoming a profitable speculation. In estimating the use of any particular insect, we must not forget to take into account the fact that many, from which civilized man obtains no direct benefit, are of the greatest use to thousands of our less favoured fellow creatures; neither must we forget that scientific research has, in many cases, discovered the means of supplying wants by other means, for which, for ages, man was entirely dependent upon insects. This last remark cannot be better illustrated than by considering the produce of the honey bee. What value was formerly attached to the
product of the bee, we may estimate when we remember that honey is one of the blessings promised to the Israelites-" And ye shall inherit a land flowing with milk and honey." In the present day there are, in many parts of the world, districts where bee-culture is extensively carried on; in Palestine extensive apiaries are very common, the country being admirably adapted to the requirements of the bee; the valleys abound in aromatic plants, from which the most delicious honey is obtained. Large amounts of honey and wax are also obtained from the wild swarms that live in the rocks. These, modern travellers inform us, are particularly abundant in the wilderness of Judea their swarms being almost innumerable in the clefts and fissures of the rocks; here the Bedouins collect honey, and convey it to the towns throughout Palestine for sale.
In many parts of Europe bee-culture is carried on to an extent we should scarcely have expected in the present day; it is no uncommon circumstance for a single bee farmer to possess a thousand hives, others from two to even 5000; and this is a profitable employment in many parts of Spain and Italy. In Catholic countries the use of wax is very great. In old books treating upon this subject, I have been surprised to find accounts of bee-farmers being richer than growers of corn; this was in catholic times; but the diminished importance of the honey-bee to Europe, arises from the discovery of the mode of extracting sugar from the sugar-cane, and of other products from which the best candles are now manufactured having in so great a degree superseded the use of wax. Notwithstanding these circumstances, both honey and wax are still largely consumed in this country, whilst in India the amount of honey consumed is something almost incalculable. In all tropical countries honey bees are very numerous, and their products of the greatest value; where an insect of this kind is abundant, its product is sure to be found to be beneficially useful.
There is, perhaps, no product more valuable derived from insects than that which can be applied to arts and manufacture; I shall, therefore, now mention a few from which are obtained some of the most valuable dyes. One of the oldest references to colour is to be found in Holy writ—and we find it in the order given for building the tabernacle: "Thou shalt make the tabernacle with ten curtains of fine twined linen, and blue, and purple, and scarlet." The oldest scarlet dye was obtained from an insect, the Coccus Ilicis, found on a small species of oak in southern Europe, in Persia, Palestine, and Arabia, &c. This red dye is one of the most imperishable known, and
is more fixed than the red dye obtained from the cochineal, but cannot be obtained in sufficient quantities, or at so cheap a rate, as that article; in fact, the abundance of cochineal has caused it to supersede several other brilliant dyes obtained from other insects.
There can be no doubt that cochineal is the most valuable insect product used in dying; it is a Mexican product chiefly. The cochineal insect feeds upon a species of fig, plantations of which are grown for that purpose. In the insect-room at the British Museum is a large picture of one of these plantations, in which people are seen employed in picking the Cocci off the prickly fig-trees, whilst a sort of grandee stands by overlooking their labour; on one side of the picture are the houses in which the cochineal is prepared for the market. The insects are collected principally by women, who brush them off the plant. Having collected a number, they are thrown into boiling water and killed; they are afterwards dried in the sun or in ovens for that purpose.
From another insect, of the same family as the Coccus of the Cochineal, is obtained the product known as Lac. Now Lac is used for so many purposes that its value will become apparent if I only allude to one or two; it is used largely in the manufacture of some of the strongest glues; in varnishes it is a most indispensible ingredient, and it is the product from which japan is made. In China, India, and Japan, it is one of the most common and useful varnishes used for all kinds of furniture, as well as for ornamental articles. The substance lac is composed of accumulated masses of the bodies of the little insect called Coccus; these insects, like the common plant-lice seen on the roses in our gardens, accumulate in masses on the branches of shrubs and trees; from these they imbibe the sap. They are scale-like insects and one is very common in this country, it is found upon the vine; it is always covered over with a white cottony substance, which many of you have doubtless observed. The lac insect is named Coccus lacca, lacca signifying the juice of a tree; in fact, old authors had no idea that it was an insect at all, and describe lac as a vegetable product. A valuable dye is also obtained from lac in conjunction with other substances; this scarlet colour is used in dying cloth for the army.
There are several other species of Cocci, from which dyes are obtained, all more or less valuable, whilst others furnish large quantities of wax used in varnishes as well as in the manufacture of candles in other countries.
(To be continued.)