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to veyances of lands, and registering them, res in order to secure men's titles ; but this * has been objected to by the landed inte* * rest in parliament, chiefly from motives

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INSCRIBED, in geometry. A figure is said to be inscribed in another, when all its angles touch the sides or planes of the other figure.

INSCRIPTION, a title or writing carved, engraved, or affixed to any thing, to give a more distinct knowledge of it, or to transmit some important truth to pos. terity. The inscriptions mentioned by Herodotus and Diodorus Siculus sufficiently shew that this was the first method of conveying instruction to mankind, and transmitting the knowledge of history and sciences to posterity ; thus the ancients engraved upon pillars both the principles of sciences, and the history of the world. , Pisistraus carved precepts of ... husbandry on pillars of stone; and, the *... treaties of ... between the Romans and Jews were engraved on plates 3. of brass. Hence, antiquarians have been a very curious in examining the inscriptions on ancient ruins, coins, medals, &c.

INSECTS, in natural history. We * * have, under the article ENtomology, *... given an account of the Linnaean system of this department of natural history. ** we shall, in this place, enumerate some e - - - * of those circumstances which form the line of distinction between insects and other animals. Insects are not furnished with red blood, but instead of it their vessels contain a transparent lymph. This may serve to distinguish them from the superior, animals, but it is common to

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* then a with many of the inferior; though Cuvier has lately demonstrated the exist

ence of a kind of red blood in some of * the v-ermes. They are destitute of internal b-ranes; but, in place of them, are furnished with a hard external covering, to to which the muscles are attached, which !o serves them both for skin and bones; they are likewise without a spine formed to of vertebrae, which is found in all the superior classes of animals. They are furnished with articulated legs, six or more; this circumstance distinguishes them from all other animals destitute of a spine formed of vertebrae. A very great number of insects undergo a metamorphosis: this takes place in all the winged insects. * They frequently change their skin in the to progress of their growth. A very great a number or finsects are furnished with jaws placed uransversely. The wings with which a very great o VOL. WI.

number of insects are furnished distinguish them from all other animals, which are not furnished with a spine composed of vertebrae. Insects are generally oviparous; scorpions and aphides, during the summer months, are viviparous. Insects have no nostrils, are destitute of voice: they are not furnished with a distinct heart, composed of ventricle and auricle. Incubation is not necessary for hatching their eggs. Insects, like all other organized bodies, which form the animal and vegetable kingdoms, are composed of #. and solids. In the four superior classes of animals, viz. quadrupeds, birds, reptiles and fishes, the bones form the most solid part, and occupy the interior part both of the trunk and limbs; they are surrounded with muscles, ligaments, cellular membrane, and skin. The matter is reversed in the class of insects; the exterior part is most solid, serving at the same time both for skin and bones; it encloses the muscles and internal organs, gives firmness to the whole body, and, by means of its articulations, the limbs, and different parts of the body, perform their various motions. In many insects, such as the crab, lobster, &c., the external covering is very hard, and destitute of organization; it is composed of a calcareous earth, mixed with a small quantity of gelatine, formed by an exudation from the surface of the body. As its great hardness would check the growth of the animal, nature has provided a remedy; all of these crustaceous insects cast their shell annually. See CRusts. The skin of most of the other insects is softer and organized, being formed of a number of thin membranes, adhering closely to one another, and putting on the appearance of hern. It owes its greater softness to a larger proportion of gelatine. The muscles of insects consist of fibres formed of fasciculi; there are commonly but two muscles to produce motion in any of their limbs, the one an extensor, the other a flexor. These muscles are commonly attached to a tendon, composed of a horny substance, connected to the part which they are des. tined to put in motion. In most insects, the brain is situated a little above the osophagus; it divides into two la branches, which surround the oesophaus, and unite again under it, from which junction a whitish nervous cord proceeds, corresponding to the spinal marrow of the superior animals, which extends the whole length of the body, Ros in its course twelve or thirteen o

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* knots or ganglions, from each of which small nerves proceed to different parts of the body. Whether insects be endowed with any senses different from those of the superior animals cannot easily be ascertained. It appears pretty evident that they possess vision, hearing, smell, and touch ; as to the sense of taste, we are left to conjecture, for we are acquainted with no facts, by which we can prove that insects do or do not enjoy the sense of taste. The eyes of insects are of two kinds; the one compound, composed of lenses, large, and only two in number; the other are small, smooth, and vary in number, from two to eight. The small lenses, which form the compound eyes, are very numerous; they amount, in some insects, to many hundreds. The far greater number of insects have only two eyes, but some have three, as the scolopendra; some four, as gyrinus; some six, as scorpions; some eight, as spiders. The eyes of insects are commonly immoveable; crabs, however, have the power of moving their eyes. That insects are endowed with the sense of hearing can no longer be disputed, since frog-hoppers, crickets, &c. furnish us with undeniable proofs of the fact. Nature has provided the males of these insects with the means of calling their females, by an instrument fitted to produce a sound which is heard by the latter. The male and female death-watch give notice of each other's presence, by repeatedly striking with their mandibles against old wood, &c. their favourite haunts. Their ears have been discovered to be placed at the root of their antennae, aud can be distinctly seen in some of the larger kinds, as the lobster. That insects enjoy the faculty of smelling is very evident; it is the most perfect of all their senses.— Beetles, of various sorts, the different species of dermestes, flies, &c. perceive at a considerable distance the smell of ordure and dead bodies, and resort in swarms to the situations in which they occur, either for the purpose of procuring food, or laying their eggs. Insects feed on a great variety of substances; there are few things either in the vegetable or animal king. doms which are not consumed by some of them. The leaves, flowers, fruit, and even the ligneous parts of vegetables, af. ford nourishment to a very numerous class; animal bodies, both dead and alive, even man himself, is preyed on by many of them : several species of the louse, of the acarus, of the gnat, and the common flea, draw their nourishment from the surface of his body; the pulex ulcerans pe

netrates the cuticle, and even enters his flesh. A species of gadfly, oestrus hominis, deposits its eggs under his skin, where the larvae feed. Other caterpillars insinuate themselves into different cavities of his body. Ail the inferior animals have their peculiar parasitical insects, which feed on them during their life. There are some insects which can feed only on one species. Many caterpillars, both of moths and butterflies, feed on the leaves of some particular vegetable, and would die, could they not obtain this. There are others which can make use of two or three kinds of vegetables, but which never attain full perfection, except when they are fed on one particular kind; for example, the common silk-worm, which eats readily all the species of mulberry, and even common lettuce, neither attains so great a size, nor produces so much silk, as when fed on the white mulberry.— There are a great many which feed indiscriminately on a variety of vegetables. Almost all herbivorous insects eat a great deal, and very frequently; and most of them perish, if deprived of food but for a short time. Carnivorous insects can live a long while without food, as the carabus, ditiscus, &c. As many insects cannot transport themselves easily in quest of food, to places at a distance from one another, nature has furnished the perfect insects of many species with an instinct, which leads them to deposit their eggs in situations where the larvae, as soon as hatched, may find that kind of food which is best adapted to their nature. Most of the butterflies, though they flutter about, and colect the nectareous juice of a variety of flowers, as food for themselves, always deposit their eggs on or near to those vegetables destined by nature to become the food of their larvae. The various species of ichneumon deposit their eggs in the bodies of those insects on which their larva: feed. See le HNEUMox. The sirex and sphex are likewise careful to deposit their eggs in situations where their larvae, when hatched, may find subsistence. The sphex figulus deposits its eggs on the bodies of spiders which it has killed, and encloses it in a cell composed of clay. Some insects, at different periods of their existence, makes use of aliment of very difierent properties; the larvae of some are carnivorous, while the perfect insect feeds on the nectareous juice of flowers: e. g. sirex, ichneumon, &c. The larvae of most of the lepidopterous insects feed on the leaves and young shoots of vegetables. while the perfect insects either take no food at all, or subsist on the sweet juice which they extract from flowers: indeed, the construction of their mouths prevents theon from taking any other than fluid food. We shall now refer to the functions of insects: beginning with respiration, which is the act of inhaling and exhaling the air into and out of the lungs. Quadrupeds, birds, and most of the amphibia, breathe 1hrough the mouth and nostrils. The air, when received into the lungs, is mixed with the blood, and imparts to it something necessary, and carries off something noxious. Some authors have asserted, that insects have no lungs; but later experiments and observations show, that no species wants them, or, at least, something similar to them ; and in many insects they are larger in proportion to their bodies than in other animals. In most of them they lie at or near to the surface of the body, and send out lateral pores or tracheae. The respiration of insects has attracted the attention of many naturalists, and it is found that insects do not breathe through the mouth or nostrils; that there are a number of vessels, for the reception of air, placed along on each side of the body, which are commonly called spiracula, which are subdivided into a number of smaller vessels, or bronchiae; that the vessels, or tracheae, which proceed from the pores on the sides, are not composed of a simple membrane, but are tubes formed of circular ruge; that the spiracula are distinguishable, and are covered with a small scaly plate, with an opening in the middle like a button-hole, which is furnished with membranes, or threads, to prevent the admission of extraneous bodies. Insects are the only animals without vertebrae, in which the sexes are distinguished. Copulation is performed in them by the introduction of the parts of genertion of the male into those of the female. All insects are either male or female, except in a few of the genera of the order Hymenoptera, such as the bee, ant, &c. where individuals are to be found, which are neither male nor female; and on that account called neuters. Among the bees, the neuters form the far greater part of the community, and perform the office of labourers. Among the ants, the neuters are very numerous, and constitute the only active members of the society. It has been alleged, that these neuters are nothing but females, whose parts have not been developed for want of proper nou. rishment. Oliver, however, after strict examination, is disposed to think them

really different, though he does not adduce facts sufficient to establish his opinion. The parts which distinguish the male from the female may be divided into two classes, viz. 1. Those which are not directly connected with generation. 2. Those which are absolutely necessary for the purposes of generation. The circumstances which have no direct communication with generation, which serve to point out the distinction between the sexes, are the difference of size observable in the male and female ; the brightness of the colour in each; the form and number of articulations of the antennae; the size and form of their wings; the presence or absence of a sting; the male is always smaller than the female; the female ant is nearly six times larger than the male; the female cochineal is from twelve to fifteen times the size of the male; the female termes is two hundred or three hundred times the size of the male ; the colours of the male are commonly much more brilliant than those of the female ; this is particularly the case in lepidopterous insects; in some insects, the colour of the male is totally different from that of the female; the antennae of the male are - commonly of a different form, and larger than those of the female ; frequently the males are furnished with wings, while the females have none; the lampy ris, coccus, and blatta, and several moths, afford an example of this ; the female bee is furnished with a sting, while the male is destitute of one ; the males of some insects are furnished with sharp prominent points, resembling horns, situated either on the head or breast, which are either not perceptible, or very faintly marked, in the female. The parts essential to generation afford the best distinguishing mark; in most insects they are situated near the extremity of the rectum ; by pressing the abdomen near to the anus, they may frequently be made to protrude; but the parts of generation are not always situated near the anus: in the spiders, they are situated in the feelers; in the libellula, the male organ is situated in the breast, while that of the female is placed at the antis

The eggs of insects are of two sorts: the first membranaceous, like the eggs of the tortoise, and the other reptiles; the other covered with a shell like those of the birds; their figure varies exceedingly ; some are round, some elliptical, some lenticular, some cylindrical, some pyramidal, some flat, some square, but the round and oval are the most common. The eggs of insects seldom increase in size, from the time they have been deposited by the parent till they are hatched; those of the tenthredo, however, and of some others, are observed to increase in bulk. At first there is nothing to be perceived in the eggs of insects but a watery fluid ; after some little time, an obscure point is observable in the centre, which, according to Swammerdam, is not the insect itself, but only its head, which first acquires consistence and colour: and the same author alleges, that insects do not increase in bulk in the egg, but that their arts only acquire shape and consistence. {.. the shell of the egg, there is a thin and very delicate pellicle, in which the insect is enveloped, which may be compared to the chorion and amnios, which surround the foetus in quadrupeds. The little insect remains in the egg till the fluids are dissipated, and till its limbs have acquired strength to break the egg, and make its escape ; the different species of insects remain inclosed in the egg for very different periods; some continue inclosed only a few days, others remain for several months. The eggs of many insects remain without being hatched during the whole winter, and the young insects do not come forth from them till the season. at which the leaves of the vegetables, on which they feed, begin to expand. When the insects are ready to break their prison, they commonly attempt to pierce the shell with their teeth, and form a circular hole, through which they put forth first one leg, and then another, till they extricate themselves entirely. Insects are by far the most numerous class of animals: about eleven thousand species have been described by Gmelin, in the last edition of the “System of Nature:” a great many more have been described by other naturalists since the publication of that work ; and a very considerable number are to be met with in the cabinets of the curious, which have not as yet been described by any author. In those parts of the world which we are best acquainted with, we may easily suppose that many species of insects exist, which have hitherto escaped notice. The minuteness of some insects makes them easily overlooked ; the agility of others renders the catching of them difficult; the retired situations which many of them haunt favour their concealment. In the unexplored parts of America, Asrica, and Asia, many thousand species must exist utterly unknown to naturalists: all these circumstances render it very probable, that not one half of the insects which exist in the world have hitherto been de

scribed. In order to exhibit the proportion they bear to plants, it may be proper to remark, that, as inhabitants of England, eight thousand species have been already described, and only three thousand plants. Insects afford nourishment to a great number of the superior animals: many of the fishes, reptiles, and birds, draw the principal part of their sustenance from that source. The immense swarms of dif. ferent species of crab, which abound in every sea, directly or indirectly form the principal part of the food of the cod, haddock, herring, and a great variety of fishes. The snake, lizard, frog, and many other reptiles, feed both on land and aquatic insects. Gallinaceous fowls, and many of the small birds, &c. feed on insects. Swallows, indeed, feed entirely on winged insects. They afford food, likewise, to many of the mammalia, viz. to many species of the bat, to the ant-eater, &c. and even to man himself. Many species of crab, viz. lobster, common crab, shrimp, prawn, land-crab, &c. are reckoned delicacies. The larvae of some coleopterous insects and locusts form part of the food of man. Insects, likewise, by consuming decayed animal and vegetable matter, which, if left to undergo the putrefactive process on the surface of the ground, might taint the atmosphere with pestilential vapours, preserve the air pure for the respiration of man and other animals INSERTION, in anatomy, the close conjunction of the vessels, tendons, fibres, and membranes of the body, with some other parts. INSOLATION, in chemistry, a term sometimes made use of to denote that exposure to the sun, which is made in order to promote the chemical action of one substance upon another: one of the most striking experiments of this kind is that of the exposure of vegetables, as freshgathered cabbage-leaves, in a glass jar of water, to the rays of the sun, by the action of which a large quantity of pure oxygen gas is obtained. INSOLUBILITY, in chemistry. The insolubility of a substance in a fluid, which is the medium of chemical action, has an influence on that action somewhat simi. lar to that of cohesion, and is nothing but a modification of it, in relation to the fluid in which it is exerted. If substances in their liquid state be made to act on each other, their action will meet with little foreign resistance, and will be, in a great measure, proportioned to their affinity and quantity; but if one of them be solid, and be farther insoluble in the fluid, which is the medium of action, the insolu

ble matter must present comparatively few points of contact ; it must be always withdrawn from the sphere of action, and of course, if it be opposed to a combinapion, it can act with comparatively little energy. From the same cause, if it be a compound, and be acted on by any substance tending to combine with one of its principles, its insolubility must in some measure protect it, as abstracting it from the action of the decomposing substance.

INSOLV ENT debtors. Insolvent acts are statutes passed for the purpose of releasing from prison, and sometimes from their debts, persons whose transactions have not been of such a nature as would subject them to the bankrupt laws. Their discharge is usually from all suits and im.

prisonment, upon delivering up all their

estates and effects, real and personal, for the benefit of their creditors. INSPIRATION, among divines, &c. implies the conveying of certain extraordinary and supernatural notices or motions into the mind; or it denotes any supernatural influence of God upon the mind of a rational creature, whereby he is formed to any degree of intellectual improve

ments, to which he could not, or would

not, in fact, have attained in his present circumstances, in a natural way. Thus the prophets are said to have spoken by divine inspiration. Some authors reduce the inspiration of the sacred writers to a particular care of Providence, which prevented any thing they had said from failing or coming to nought; maintaining, that they never were really inspired either with knowledge or expression. According to others, inspiration is no more than a direction of the Holy Spirit, which never permitted the sacred writers to be mistaken. It is a common opinion, that the inspiration of the Holy Spirit regards only the matter, not the style or words. Theological writers have enumerated several kinds of inspiration; such as “an inspiration of superintendency,” in which God does so influence and direct the mind of any person, as to keep him more secure from error in some various and complex discourse, than he would have been merely by the use of his natural faculties; “ plenary, superintendent inspiration,” which excludes any mixture of error from the performance so superintended ; “inspiration of elevation,” where the faculties act in a regular, and, as it seems, in a common manner, yet are raised to an extraordinary degree, so that the composer shall, upon the whole, have more of the true sublime or pathetic, than natu

which he be

ral genius could have given; and “inspiration of suggestion,” when the use of the faculties is superseded, and God does, as it were, speak directly to the mind, making such discoveries to it, as it could not otherwise have obtained, and dictating

the very words in which such discoveries .

are to be communicated, if they are designed as a message to others. It is generally allowed, that the New Testament was written by a superintendent inspiration; for without this the discourses and doctrines of Christ could not have been faithfully recorded by the Evangelists and Apostles; nor could they have assumed the authority of speaking the words of Christ, and evinced this authority by the actual exercise of miraculous powers; and, besides, the sacred writings bear many obvious internal marks of their divine original, in the excellence of their doctrines, the spirituality and elevation of their design, the majesty and simplicity of their stile, the agreement of their various parts, and their efficacy on mankind; to which may be added, that there has been in the Christian church, from its earliest ages, a constant tradition, that the sacred books were written by the extraordinary assistance of the Spirit, which must at least amount to superintendent inspiration; but it has been controverted, whether this inspiration extended to every minute circumstance in their writings, so as to be in the most absolute sense plenary. Jerome, Grotius, Erasmus, Episcopius, and many others, maintain, that it was not: whilst others contend, that the emphatical manner in which our Lord speaks of the agency of the spirit upon them, and in which they themselves speak of their own writings, will justify our believing that their inspiration was plenary, unless there be very convincing evidence brought on the other side to prove that it was not ; and if we allow, it is said, that there were some errors in the New Testament, as it came from the hands of the Apostles, there may be great danger of subverting the main purpose and design of it; since there will be endless room to debate the importance both of facts and doctrines. See Doddridge’s Lectures. INSTALMENT, the instating or establishing a person in some dignity. This word is chiefly used for the induction of a dean, prebendary, or other ecclesiastical dignitary, into the possession of his stall, or other F. seat, in the cathedral to ongs. It is also used for the ceremony whereby the knights of the garter are placed in their rank, in the

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