Chapter L: M N is a guide for the eye, in order to direct it in the axis of the (4)
To view the particles of the blood, take a small drop of it when warm, and spread it as thin as possible upon a flat piece of glass. By diluting it a little with warm water, some of the larger particles will divide from the smaller, and many of them will be subdivided into still smaller; or a little drop of blood may be put into a capillary tube of glass, and be then presented before the microscope. Mr. Baker advises the mixing the blood with a little warm milk, which he says, will cause the unbroken particles to be very distinctly seen. But the most accurate observer of these particles was Mr. Hewson, and he says they have been termed globules with great impropriety, being in reality flat bodies. When we consider how many ingenious persons have been employed in examining the blood with the best microscopes, it appears surprizing that the figure of the particles should be mistaken; but the wonder is lessened when we reflect how many obvious things are overlooked, till our attention is particularly directed towards them; and besides, the blood in the human subject, and in quadrupeds, is so full of these particles, that it is with great difficulty they can be seen separate, until the blood is diluted. It was by discovering a proper method to effect this, that Mr. Hewson was indebted for his success. He diluted the particles with serum, in which they would remain undissolved, and as he could dilute them to any degree with the serum, he could easily examine the particles distinct from each other; for example, take a small quantity of the serum of the human blood, and shake a piece of crassamentum in it, till it be coloured a little with the red particles; then with a soft hair pencil spread a little of it on a piece of thin glass, and place this glass under the microscope, in such a manner as not to be quite horizontal, but rather higher at one end than the other; by which means the serum will flow from the higher to the lower extremity, and as it flows, some of the particles will be found to swim on their flat sides, and will appear to have a dark spot in the middle; others will turn over from one side to the other, as they roll down the glass.
Several authors have described an apparatus for viewing the circulation of the blood in the mesentery of a frog; but as the cruelty attendant on these kinds of investigations would deprive the humane reader of a great part of the gratification which might otherwise result from them, he will probably rest satisfied with the accounts of such experiments to be met with in authors; especially as there is an abundant variety of objects on which he may exercise his ingenuity without sacrificing the nicer feelings of humanity.[44]
[44] Whatever right mankind may claim over the lives of every creature
that is placed in a subordinate rank of being to themselves, in
respect of food and self-defence, as well as for the improvement of
science, and their judicious and ingenious application to the various
purposes of use and ornament in human life, we certainly cannot, on
the principles of reason and justice, assert a privilege to gratify a
wanton curiosity, or the sports of an inordinate fancy, by the
exercise of an unnecessary cruelty over them. The immortal SHAKSPEARE,
in a passage which has often been quoted, says,
------- the poor beetle that we tread upon
In corporal sufferance finds a pang as great
As when a giant dies.
It may, however, be doubted whether this particular instance is
strictly conformable to fact; different animals certainly possess
different degrees of sensibility, and some are consequently more
susceptible of pain than others. It is a remarkable circumstance that
the Hippobosca equina, or Horse-fly, will live, run, nay even
copulate, after being deprived of its head; most flies will survive
that loss for some time, and the loss of a leg or two does not prevent
their appearing as lively and alert as if they had sustained no
injury. Many insects, on being caught, will freely and voluntarily
part with their limbs to escape; and it is well known that lobsters
shed their claws. Numbers of other instances might be adduced, but on
this subject it may be prudent not to enlarge.
Montaigne remarks, that there is a certain claim of kindness and
benevolence which every species of creatures has a right to, from us.
It is to be regretted, that this general maxim is not more attended to
in the affairs of education, and pressed home upon tender minds in its
full extent and latitude; the early delight which children discover in
tormenting different animals should by all possible means be
discouraged, as, by being unrestrained in such sports, they may at
least acquire a habit of confirmed inattention to every kind of
suffering but their own, if not progressively be led to the
perpetration of more atrocious acts of cruelty. The supreme court of
judicature at Athens thought an instance of this sort not below its
cognizance, and punished a boy for putting out the eyes of a poor bird
that had unhappily fallen into his hands; and the inimitable HOGARTH,
“the great painter of mankind,” has in his “Five Stages of Cruelty,”
admirably depicted the consequences which may result from an early
indulgence of a propensity towards cruelty.
In order to awaken as early as possible in the minds of children an
extensive sense of humanity, it might be prudent to indulge them with
a view of several sorts of insects as magnified by the microscope, and
to explain to them that the same marks of divine wisdom prevail in the
formation of the minutest insect, as in the most enormous leviathan;
that they are equally furnished with whatever is necessary, not only
for the preservation, but the happiness of their beings, in that class
of existence which Providence has assigned them: in a word, that the
whole construction of their respective organs distinctly and
decisively, proclaims them the objects of divine benevolence, and
therefore they justly ought to be so of ours. EDIT.
OF ANIMALCULA IN INFUSIONS, &C.
These require little or no preparation. The first object is to procure them, the second, to render them visible by the microscope. A few observations, however, may be of use. Many drops of water may be examined before any can be found; so that if the observer be too hasty, he may be easily disappointed, though other parts of the same water may be fully peopled by them.
The surface of infused liquors is generally covered with a thin pellicle, which is easily broken, but acquires thickness by standing; the greatest number of animalcula are generally to be found in this superficial film.
In some cases it is necessary to dilute the infusions; but this is always to be done with distilled water, and that water should be examined in the microscope before it is made use of: the neglect of this precaution has been a source of many errors.
Animalcula are in general better observed when the water is a little evaporated, as the eye is not confused, nor the attention diverted by a few objects. To separate one or two animalcula from the rest, place a small drop of water on the glass near that of the infusion; make a small neck or gutter between the two drops with a pin, which will join them together; then the instant you perceive that an animalculum has traversed the neck or gutter, and entered the drop, cut off the communication between the two drops.
To procure the eels in paste, boil a little flower and water, till it becomes of a moderate consistence; expose it to the air in an open vessel, and beat it together from time to time, to prevent the surface thereof from growing hard or mouldy; after a few days, especially in summer time, it will turn sower, then if it be examined with attention, you will find myriads of eels on the surface.
To preserve these eels all the year, you must keep the surface of the paste moist, by putting a little water or fresh paste from time to time to the other. Mr. Baker advises a drop or two of vinegar to be put into the paste now and then. The continual motion of the eels, while the surface is moist, will prevent the paste getting mouldy. Apply them to the microscope upon a slip of flat glass, first putting on it a drop of water, taken up by the head of a pin, for them to swim in.
To make an infusion of pepper. Bruise as much common black pepper as will cover the bottom of an open jar, and lay it thereon about half an inch thick; pour as much soft water in the vessel as will rise about an inch above the pepper. The pepper and water are then to be well shaken together; after which they must not be stirred, but be left exposed to the air for a few days, when a thin pellicle will be formed on the surface of the water, containing millions of animalcula.
The observer should be careful not to form a judgment of the nature, the use, and the operations of small animalcula, from ideas which he has acquired by considering the properties of larger animals: for, by the assistance of glasses, we are introduced as it were into a new world, and become acquainted not only with a few unknown animals, but with numerous species thereof, which are so singular in their formation and habits, that without the clearest proofs even their existence would not be credited; and while they afford fresh instances of the Creator’s power, they also give further proofs of the limits and weakness of the human understanding.
DIRECTIONS FOR FINDING, FEEDING, AND PRESERVING THE POLYPES.
These little animals are to be found upon all sorts of aquatic plants, upon branches of trees, pieces of board, rotten leaves, stones, and other substances that lie in the water; they are also to be met with upon the bodies of several aquatic animals, as on the water-snail, on several species of the monoculus, &c. they generally fix themselves to these by their tail, so that it is a very good method when you are in search of the polypes, to take up a great many of these substances, and put them in a glass full of water. If there be any polypes adhering to these, you will soon perceive them stretching out their arms, especially if the glass be suffered to be at rest for a while; for the polypes, which contract themselves on being first taken out of the water, will soon extend again when they are at rest.
They are to be sought for in the corners of ditches, puddles, and ponds, being frequently driven into these with the pieces of wood or leaves to which they have attached themselves. You may, therefore, search for them in vain at one period, in a place where at another they will be found in abundance. They are more easily perceived in a ditch when the sun shines on the bottom, than at another time. In winter they are seldom to be met with; about the month of May they begin to appear and increase.
They are generally to be found in waters which move gently; for neither a rapid stream, nor stagnant waters ever abound with them. As they are always fixed to some substance by their tails, and are very rarely loose in the water, taking up water only can signify but little; a circumstance which has probably been the cause of much disappointment to those who have searched for them.
The green polypes are usually about half an inch long when stretched out; those of the second and third sort are between three quarters of an inch and an inch in length, though some are to be found at times which are an inch and a half long.
Heat and cold has the same effect upon these little creatures, that it has upon those of a larger size. They are animated and enlivened by heat, whereas cold renders them faint and languid; they should therefore be kept in such a degree of heat, that the water may not be below temperate.
It is convenient for many experiments to suspend a polype from the surface of the water. To effect this, take a hair pencil in one hand, and hold a pointed quill in the other; with the pencil loosen the polype from the receiver in which it is kept, and gradually raise it near the top of the water, so that the anterior end may be next the point of the pencil; then lift it out of the water, and keep it so for a minute; after which, thrust the point of the pencil, together with the anterior end, by little and little under water, until no more than about the twentieth part of an inch of the polype’s tail remains above its surface; at this instant, with the pointed quill remove that part of the polype from the pencil which is already in the water, at the same time blowing against the polype, by which it will be loosened, and remain out of the water.
When the polypes were first discovered, Mr. Trembley had some difficulty to find out the food which was proper for them; but he soon discovered, that a small species of the millepede answered the purpose very well: the pulices aquatices have also been recommended. The small red worms, which are to be found on the mud-banks of the Thames, particularly near the shores, answer the purpose also, they are easily found when the tide is out, when they rise in such swarms on the surface of the mud, that it appears of a red colour. These worms are an excellent food for the polype. If a sufficient quantity be gathered in November, and put into a large glass full of water, with three or four inches of earth at the bottom, you will have a supply for the polypes all the winter. They may also be fed with common worms, with the larva of gnats and other insects, and even with butcher’s meat, &c. if it be cut small enough.
River, or any soft water, agrees with them; but that which is hard and sharp prevents their thriving, and generally kills them in a few days. The worms with which they are fed should be always cleansed before you feed the polypes with them.
The polypes are commonly infested with little lice; from these it is necessary to free them, in order to preserve your polypes in a good state of health. They may be cleansed from the lice by rubbing them with a hair pencil; this cannot be easily done, unless they adhere to some substance: so that if they are suspended from the surface of the water, you must endeavour to get them to fix themselves to a piece of packthread; when they are fastened thereto, you may then rub them with a hair pencil, without loosening them from the thread.
The lice which torment the polype are not only very numerous, but they are also very large proportionably to its size: they may be said to be nearly as large with respect to them, as a common beetle is to us. If not rubbed off, they soon cover their bodies, and in a little time totally destroy them.
To preserve the polypes in health, it is also necessary often to change the water they are kept in, and particularly after they have done eating; it is not sufficient to pour the water off, all the polypes should be taken out, and the bottom and sides of the vessel rubbed from the slimy sediment adhering thereto; this is caused by their fæces, and is fatal to them if not cleaned away. The fæces often occasion a species of mortification, which daily increases; its progress may be stopped by cutting off the diseased part. To take them out, first loosen their tails from the sides or bottom of the glass; then take them up one by one, with a quill cut in the shape of a scoop, and place them in another glass with clean water; if they cling to the quill, let it remain a minute or two in the water, and they will soon disengage themselves.
They are preserved best in large glasses that hold three or four quarts of water; for in a glass of this size the water need not be renewed so often, particularly, if the fæces are taken out from time to time with the feathered end of a pen, to which they readily adhere; and further, the trouble of feeding each individual is in some measure saved, as you need only throw in a parcel of worms, and let the polypes divide them for themselves.
To observe with accuracy the various habitudes, positions, &c. of this little animal, it will be necessary to place some of them in narrow cylindrical glasses; then, by means of the microscope, Fig. 3. Plate VI. you may observe them exerting all their actions of life with ease and convenience; the facility with which the lens of the fore-mentioned microscope may be moved and placed in any direction, renders it a most convenient instrument for examining any object that requires to be viewed in water.
It is also very proper to dry some of them, and place them between talcs in a slider; this, however requires some dexterity and a little practice; though, when executed with success, it fully rewards the pains of the observer. Choose a proper polype, and put it into a small concave lens, with a drop of water; when it is extended, and the tail fixed, pour off a little of the water, and then plunge it with the concave into some spirit of wine contained in the bowl of a large spoon; by this it is instantly killed, the arms and body contracting more or less; rub it gently while in the spirit with a small hair pencil, to cleanse it from the lice.
The difficulty now begins; for the parts of the polype, on being taken out of the spirit, immediately cling together, so that it is not practicable to extend the body, and separate the arms on the talc, without tearing them to pieces; therefore the only method is, to adjust them upon the talc while in the spirit: this may be done by slipping the talc under the body of the polype, while it lies in the spirit, and displaying its arms thereon by the small hair pencil and a pair of nippers; then lift the talc, with the polype upon it, out of the spirit; take hold of it with the nippers in the left hand, dip the pencil in the spirit with the right hand, and therewith dispose of the several parts, that they may lie in a convenient manner, at the same time brushing away any lice that may be seen upon the talc; now let it dry, which it does in a little time, and place the talc carefully in the hole of the slider. To prevent the upper talc and ring pressing on the polype, you must cut three pieces of cork, about the bigness of a pin’s head, and the depth of the polype, and fix them by gum in a triangular position, partly on the edges of the said talc, and partly to the sides of the ivory hole itself; the upper talc may then be laid on these corks, and pressed down by the ring as usual.[45]
[45] Baker on the Polypes.
OF VEGETABLES.
It were to be wished a satisfactory account could here be given of all the preparations which are requisite to fit for the microscope the objects of the vegetable kingdom. Dr. Hill is the only writer who has handled this subject. I shall, therefore, extract from his “Treatise on the Construction of Timber,” what he has said; this, together with the improvements I have made on the cutting engine, will enable the reader to pursue the subject and extend it further, both for his own pleasure, and the advantage of the public.
THE MANNER OF OBTAINING THE PARTS OF A SHOOT SEPARATE.
In the beginning of April, take a quantity of young branches from the scarlet oak, and other trees. These are first cut into lengths, of the growth of different seasons; and then part is left entire, part split, and the rest quartered. In this state they are put into a wicker basket, with large openings, or of loose work, and a heavy stone is put in with them; a rope is tied to the handle of the basket, and it is thrown into a brook of running water: at times it is taken up, and exposed a little to the air; it is frequently shook about under water, to wash off filth; and once in ten days the sticks are examined.
By degrees the parts loosen from one another, and by gentle rubbing in a bason of water just warmed, they will be so far separated, that a pencil brush will perfect the business, and afford pieces of various sizes, pure, distinct, and clean. One part will in this way separate at one time, and another, at another; but by turning the sticks to the water, and repeating the operation, in the course of four or five weeks every part may be obtained distinct. They are best examined immediately; but if any one wish to preserve them for repeated inquiries, it may be done in this manner: dissolve half an ounce of alum in two quarts of water; drop the pieces thus separated, for a few moments, into this solution, then dry them upon paper, and put them up in vials of spirit of wine, no other fluid being so well adapted to preserve these tender bodies.
TO PREPARE THE RIND FOR OBSERVATION.
As the vessels of the rind are of different diameters in various trees, though their construction and that of the blebs is perfectly the same in all, it will be best to choose for this purpose the rind of a tree wherein they are largest. The rind of the ash-leaved maple is finely suited. A piece of this may be obtained of two inches long, and will very successfully answer the intention. Such a piece being prepared without alum or spirit, but dried from the water in which it had been macerated, it is to be impregnated with lead in the following manner, to shew the apertures by their colour.
Dissolve one drachm of sugar of lead in an ounce and an half of water; filter this through paper, and pour it into a tea-cup. Clip off a thin slice of what was the lower end of the piece of rind as it grew on the tree, and plunge it near an inch deep into the liquor; keep it upright between two pieces of stick, so that one half or more may be above the water; whelm a wine-and-water glass over the tea-cup, and set the whole in a warm place. When it has stood two days, take it out, clip off all that part which was in the liquor, and throw it away.
The circumstances here mentioned, trivial as they may seem, must be attended to: the operation will not succeed, even if the covering-glass be omitted; it keeps a moist atmosphere about the rind, and makes its vessels supple.
While this is standing, put into a bason two ounces of quick lime, and an ounce of orpiment; pour upon them a pint and an half of boiling water; stir the whole together, and when it has stood a day and a night, it will be fit for use. This is the “liquor probatorius vini” of some of the German chymists; it discovers lead when wines are adulterated with it, and will shew it any where.
Put a little of this liquor in a tea-cup, and plunge the piece of rind half way into it.
In the former part of this experiment, the vessels of the rind have been filled with a solution of lead, that makes of itself no visible alteration in them; but this colourless impregnation, when the orpiment lixivium gets to it, becomes of a deep brown; the vessels themselves appear somewhat the darker for it; but these dots, which are real openings, are now plainly seen to be such, the colour being perfectly visible in them, and much darker than in the vessels. This object must be always viewed dry.
If a piece of the rind, thus impregnated, be gently rubbed between the fingers, till the parts are separated, we shall be able in one place or other, to get a view of the vessels all round, and of the films which form the blebs between them.
Every part of the rind, and every coat of it, even the interstitial place between its innermost coat and bark, are filled with a fine fluid. The very course and progress of the fluid may be shewn in this part, even by an easy preparation; only that different rinds must be sought for this purpose, the vessels in some being larger than in others. Repeated trials have shewn me that the whole progress may be easily marked in the three following kinds, with only a tincture of cochineal.
Put half an ounce of cochineal, in powder, into half a pint of spirit of wine; set it in a warm place, and shake it often for four days; then filter off the clear tincture. Put an inch depth of this into a cup, and set upright in it pieces of the rind of ash, white willow, and ozier, prepared as has been directed, by maceration in water; for in that way one trouble serves for an hundred kinds. Let an inch of the rinds also stand up out of the tincture. After twenty-four hours take them out, clip off the part which was immersed in the fluid, and save the rest for observation.
TO PREPARE THE BLEA.
Cut the pieces in a fit season, either just before the first leaves of Spring, or in the Midsummer shooting time. Then we see all the wonders of the structure; the thousands of mouths which open throughout the course of these innumerable vessels, to pour their fluid into the interstitial matter.
These vessels, which are in nature cisterns of sap for the feeding the growth of the whole tree, are so large, that they are capable of being filled with coloured wax, in the manner of the vessels in anatomical injections; and this way they present pleasing objects for the microscope, and afford excellent opportunities of tracing their course and structure.
A METHOD OF FILLING THE SAP VESSELS OF PLANTS.
A great many shoots of the scarlet and other oaks are to be taken off in the Spring; they must be cut into pieces of about two inches in length, and immediately from the cutting they must drop into some warm rain water: in this they are to stand twenty-four hours, and then be boiled a little. When taken out, they are to be tied on strings, and hung up in a place where the air passes freely, but the sun does not shine. When they are perfectly dry, a large quantity of green wax, such as is used for the seals of law deeds, is to be gently melted in an earthen pipkin set in water; the water to be heated and kept boiling. As soon as the wax runs, the sticks are to be put in, and they are frequently to be stirred about. They must be kept in this state about an hour, and then the pipkin is to be taken out of the water, and set upon a naked fire, where it is to be kept with the wax boiling for two or three hours; fresh supplies of the same wax being added from time to time.
After this it is to be removed from the fire, and the sticks immediately taken out with a pair of nippers; when they are cold, the rough wax about them is to be broken off. Both ends of each stick are to be cut off half an inch long, and thrown away, and the middle pieces saved. These are then to be cut in smaller lengths, smoothed at the ends with a fine chissel, and many of them split in various thicknesses.
Thus are obtained preparations, not only of great use, but of wonderful beauty. Many trees this way afford handsome objects as well as the oak; and in some, where the sap vessels are few, large, and distinct, the split pieces resemble striped satins, in a way scarce to be credited. It is in such that the outer coats of these vessels are most happily of all to be examined.
THE METHOD OF PREPARING SALTS AND SALINE SUBSTANCES, FOR THE VIEWING THEIR CONFIGURATIONS.
Dissolve the subject to be examined in no larger a quantity of river or rain water than is sufficient to saturate it; if it be a body easily dissoluble, make use of cold water, otherwise make the water warm or hot, or even boiling, according as you find it necessary. After it is perfectly dissolved, let it rest for some hours, till, if over-charged, the redundant saline particles are precipitated, and settle at the bottom, or shoot into crystals; by which means you are most likely to have a solution of the same strength at one time as at another; that is, a solution fully charged with as much as it can hold up, and no more; and by these precautions the configurations appear alike, how often soever tried: whereas, if the water be less saturated, the proportions, at different times, will be subject to more uncertainty; and if it be examined before such separation and precipitation of the redundant salts, little more will be seen than a confused mass of crystals.
The solution being thus prepared, take up a drop of it with a goose quill, cut in fashion of a scoop, and place it on a flat slip of glass, of about three quarters of an inch in width, and between three and four inches long, spreading it on the glass with the quill, in either a round or oval figure, till it appears a quarter of an inch or more in diameter, and so shallow as to rise very little above the surface of the glass. When it is so disposed, hold it as level as you can over the clear part of a fire that is not too fierce, or over the flame of a candle, at a distance proportionable to the degree of heat it requires, which experience only can direct, and watch it very carefully till you discover the saline particles beginning to gather and look white, or of some other colour, at the extremities of the edges; then having adjusted the microscope before-hand for its reception, armed with the fourth glass, which is the fittest for most of these experiments, place it under your eye, and bring it exactly to the focus of the magnifier; and after running over the whole drop, fix your attention on that side where you observe any increase or pushing forwards of crystalline matter from the circumference towards the center.
This motion is extremely slow at the beginning, unless the drop has been over-heated, but quickens as the water evaporates, and in many kinds, towards the conclusion, produces configurations with a swiftness inconceivable, composed of an infinity of parts, which are adjusted to each other with an elegance, regularity, and order, beyond what the exactest pencil in the world, guided by the ruler and compass, can ever equal, or the most luxurious imagination fancy.
When action once begins, the eye cannot be taken off, even for a moment, without losing something worth observation; for the figures alter every instant, till the whole process is over; and in many sorts, after all seems at an end, new forms arise, different entirely from any that appeared before, and which probably are owing to some small quantity of salt of another kind, which the other separates from, and leaves to act after itself has done; and in some subjects three or four different sorts are observable, few or none being simple and homogeneous.
When the configurations are fully formed, and all the water evaporated, most kinds of them are soon destroyed again by the moisture or action of the air upon them; their points and angles lose their sharpness, become uneven and defaced, and moulder as it were away; but some few are permanent, and by being inclosed between glasses, they may be preserved months or even years.
It happens oftentimes that a drop of a saline solution can hardly be spread on the slip of glass, by reason of the glass’s smoothness, but breaks into little globules, as it would do were the surface greasy: the way to prevent this is, by rubbing the broken drop with your finger over the glass, so as to leave the glass smeared with it; on which smeared place, when dry, another drop of the solution may be spread very easily in whatever form is agreeable.
It sometimes happens, that when a heated drop is placed properly for examination, the observer finds such a cloudiness that he can distinguish nothing of the object; which is owing to saline steams that arise from the drop, covering and obscuring the object glass, and therefore must immediately be wiped away with a soft cloth or leather.
In all examinations of saline solutions by the microscope, even though made in the day-time, you must use a candle; for the configurations, being exceedingly transparent, are rendered much more distinguishable by the brown light a candle affords, than by the more white and transparent day-light; and besides, either by moving the candle, or turning the microscope, such light may be varied or directed just as the subject requires.
It may be also proper to take notice, that no kinds of microscopes are fit for these observations, but such as have an open stage, whereon the slips of glass, with the liquor upon them, may be placed readily, and in a perfect horizontal position; and moreover, where they can be turned about freely, and without disordering the fluid.
CHAP. V.
THE IMPORTANCE OF NATURAL HISTORY; OF INSECTS IN GENERAL, AND OF THEIR CONSTITUENT PARTS.
There is no human science which to a rational mind exhibits a greater variety of attractions, or which is more deserving of general esteem, than that of NATURAL HISTORY; accordingly we find, that from the earliest times in which the sciences have been promulgated, it has never been entirely destitute of its votaries; but, on the contrary, has for ages employed the lives of many learned men, as being, in fact, the study of DIVINE WISDOM displayed in the creation: the farther our researches are carried, the more striking proofs of it every where abound. In the present century, an æra particularly devoted to investigation, and propitious to discovery and improvement in various branches of science, Natural History, so far from being neglected, has been more generally cultivated, and pursued with an ardor unprecedented at any former period. Men of the first rank in literature have become indefatigable labourers in the vast and unbounded field which it presents to the eyes of an accurate and attentive observer. The animal, the vegetable, and the mineral kingdoms, have been examined with the utmost care; that confusion and perplexity which seemed unavoidably to result from a view of the immense variety of articles contained in each of those departments, and which frequently deterred persons from engaging in the pursuit, have been in a great measure removed by the introduction of systematic arrangement; by these means, the various subjects are distributed into classes and genera, enabling us to form distinct and comprehensive ideas of them. To the same methodical plan, and the nicety of discrimination thence arising, we must attribute the discovery and description of many new species; this has excited an emulation still farther to pursue the inquiry, nor need any apprehension be entertained that the subject will be exhausted, as, no doubt, an infinite variety still remains unexplored to engage the utmost attention of the philosophic mind, and fully to compensate the pains bestowed on so interesting a branch of knowledge.
Of the abundance of articles enumerated in books of Natural History, there are comparatively few, whose uses are as yet known, or their properties fully understood. The true naturalist should always bear in mind that there is a vast difference between retaining the names, and investigating the nature and peculiar qualities of the creatures to which they belong. It is highly proper, indeed necessary, that the multifarious objects of Natural History should be well ascertained and distinguished with nicety in all their varieties; the science and admirers of it are, therefore, unquestionably indebted to the able naturalists who have devoted their time, and exercised their ingenuity in devising commodious methods of arrangement, and invented systems for identifying the several subjects with accuracy, and less danger of fallacy or mistake: but all who are, or would wish to be thought naturalists, ought to consider, that the best possible mode of classification is, after all, but an introduction to Natural History. The ingenious and indefatigable LINNÆUS, who spent his life in fabricating the curious system now generally adopted, intended it certainly for the improvement of the science, as a basis for the service of knowledge and the benefit of mankind; let us be cautious not to mistake the means for the end, but in the prosecution of the science, think of the true ends of knowledge, and endeavour to promote our own instruction, and the advancement of others, with a view to the adoration of that DIVINE BEING to whom all creation is indebted for existence, and their application to the occasions and uses of life, all along conducting and perfecting the study in the spirit of benevolence.
The study of nature, or in other words, a serious contemplation of the works of GOD, is indeed a great and proper object for the exercise of our rational faculties; nor can we perhaps employ them better, than in endeavouring to make ourselves acquainted with the works of that glorious Being from whom they were received.
Though there is a great deal of pleasure in contemplating the material world, or that system of bodies into which the DIVINE ARCHITECT has so admirably wrought the mass of dead matter, with the several relations which those bodies bear to one another; there is still something more wonderful and surprizing arising from the contemplation of the animated world; by which is to be understood all those animals with which every part of the universe is furnished. The material world is only the shell of the universe; the animated world are its inhabitants.
Existence is a blessing to those beings only which are endowed with perception, and appears useless when bestowed upon dead matter, any farther than as it is subservient to beings which are conscious of their existence. Thus we find, from the bodies which lie under our observation, that matter is only made as the basis and support of animals, and that there is no more of the one than what is necessary for the exigence of the other.
There are some living creatures which are raised but just above dead matter; there are many others, but one remove from these, which have no other senses but those of feeling and taste; others have still an additional sense of hearing; others of smell, and again others of sight. It is wonderful to observe, by what a gradual progress life advances through a prodigious variety of species, before a creature is formed that possesses all these senses; and even among these, there is such a different degree of perfection in the senses which one animal enjoys beyond what appears in another, that, though the sense in different animals be distinguished by the same common denomination, it seems almost of a different nature. If, after this, we look into the several inward qualities of sagacity, or what is generally called instinct, we find them rising after the same manner imperceptibly one above another, and receiving additional improvements, according to the species in which they are implanted. This progress in nature is so very gradual, that what appears to us the most perfect of an inferior species, comes very near to the most imperfect, as we are accustomed to call it, of that which is immediately above it.
The exuberant and overflowing goodness of the SUPREME BEING, whose mercy extends to all his works, is plainly seen, as before observed, from his having made so very little matter, at least what falls within our knowledge, that does not swarm with life; nor is his goodness less visible in the diversity than in the multitude of living creatures. Had he only made one species of animals, none else could have enjoyed the happiness of existence; he has, therefore, included in his creation, every degree of life, every capacity of being. The whole chasm of nature, from a plant to a man, is filled up with diverse kinds of creatures, rising one above another, by such a gentle and easy ascent, that the little transitions and deviations from one species to the other are almost insensible. This intermediate space is so prudently managed, that there is scarce a degree of perception which does not appear in some one part of the animated world. Is the goodness or the wisdom of the DIVINE BEING more manifest in this his proceeding?
In this system of creation there is no creature so wonderful in its nature, and which so much merits our particular attention, as man, who fills up the middle space between the animal and intellectual nature, the visible and invisible world; and is that link, in the chain of beings, which has been often termed the “nexus utriusque mundi.” So that he, who in one respect being associated with angels and arch-angels, may look upon a BEING of infinite perfection as his father, and the highest order of spirits as his brethren, may, in another respect, say to corruption, “Thou art my father, and to the worm, thou art my mother and my sister.”[46]
[46] Spectator, Vol. vii. Numb. 519.
There are, however, many who form their judgments of the works of nature from external appearance only; hence they imagine, that the greatest and most magnificent are the only perfect parts of creation, and worthy of our regard. Hence they confine their attention to the more splendid and shining branches of philosophy, and are too apt to treat the other parts with coolness and indifference, not to say contempt.
But surely a true philosopher is one who diligently pursues the study of nature in all its branches; who can behold with admiration her noblest productions, yet view with pleasure the smallest of her works: in short, one who thinks every thing excellent that owes its formation to the GOD of nature; and we need only take a transient view of the smaller creatures with which the earth is peopled, to discover that they are perfect in their kind, and carry about them as strong marks of infinite wisdom, power, and beneficence as the greatest. It has been justly said, “that there is not a vegetable that grows, nor an insect that moves, but what is sufficient to confound the Atheist, and to afford the candid observer endless materials for devout adoration and praise.”
If we examine insects with attention, we shall soon be convinced of their divine origin, and survey with admiration the wonderful art and mechanism of their structure, wherein such a number of vessels, parts, and movements are collected in a single point; yet are they furnished with weapons to seize their prey, dexterity to escape their foes, every thing requisite to perform the business of their stations, and enjoy the pleasures of their conditions. What a profusion of the richest ornaments and the gayest colours are often bestowed on one little insect! and yet there are thousands of others that are as beautiful and wonderful in their kind; some are covered with shining coats of mail, others are adorned with plumes of feathers, all of them furnished with every thing that is proper to make them answer the purposes for which they were designed.
“After an attentive examination of the nature and fabric of both the least and largest animals, I cannot,” says the great and excellent Swammerdam, “but allow the less an equal, perhaps a superior degree of dignity; whoever duly considers the conduct and instinct of the one, with the manners and actions of the other, must acknowledge, that they are all under the direction and controul of a supreme and particular intelligence; which, as in the largest it extends beyond the limits of our comprehension, escapes our researches in the smallest. If, while we dissect with care the larger animals, we are filled with wonder at the elegant disposition of their limbs, the inimitable order of their muscles, and the regular direction of their veins, arteries, and nerves, to what an height is our astonishment raised, when we discover all the parts arranged in the least, and in the same regular manner! How is it possible but we must stand amazed when we reflect, that those little animals, whose bodies are smaller than the point of the dissecting knife, have muscles, veins, arteries, and every other part common to the larger animals? Creatures so very diminutive, that our hands are not delicate enough to manage, or our eyes sufficiently acute to see them.”
The subserviency of the several beings in the visible creation to one another; the order in which each of them appears in that appointed season, when only it can be conducive to the purposes of the rest; and the preservation of a sufficient number of every species, amidst the immense havoc that reigns throughout, are, among other things, proofs of the amazing and incomprehensible wisdom by which they were all formed. With what pleasure does the mind, accustomed to look up from effects to their causes, from created beings to the GREAT SOURCE OF BEING, view that unbounded beneficence, which leaves not the smallest space, capable of supporting existence of any kind, unplanted with them. There is hardly any portion of matter, or the least drop of fluid naturally found on the surface of the earth, that is not inhabited by multitudes of animals; the subterraneous regions are peopled with their minute inhabitants, and the abyss of the sea, where no human eye can penetrate, abounds with animated beings.
The air is usually considered as the great source of destruction to bodies, whether animal or vegetable; but we do not always understand by what means or in what manner it is performed. What we term destruction and decay of one substance, occasions the production and ripening a multitude of others; wherever the air is admitted, with it a thousand different things find their way; and what is usually attributed to the effects of that fluid, is in general occasioned by the multitudes of bodies with which it is fraught. Redi observed, that flesh preserved from the access of flies, would bread no maggots; and it is as constant an observation, that vegetable substances will keep a long time in whatever state they are, if the air be excluded; but as soon as it is admitted, they also produce or afford their several kinds either of animal, or minuter vegetable inhabitants. In the first of these cases, the parent flies make their way to the exposed flesh, and there deposit their eggs for the production of a new offspring; in the other, multitudes of the seeds of minute plants and ovula of animals are floating in the air, and accompany it wherever it enters; if they be thus deposited in a place proper for vegetation and accretion, they burst their inclosures, and attain their growth as regularly as the seeds of plants deposited in the earth, or the eggs of larger animals in the nest.
The same wisdom which placed the sun in the center of the system, and arranged the several planets around him in their order, has no less shewn itself in the provision made for the food and dwelling of every bird that roams in the air, and every beast that wanders in the desert; equally great in the smallest and in the most magnificent objects; in the star and in the insect; in the elephant and in the fly; in the beam that shines from heaven and in the grass that cloathes the ground. Nothing is overlooked, nothing is carelessly performed: every thing that exists is adapted with perfect symmetry to the end for which it was designed. This wisdom displayed by the Almighty in the creation, was not intended merely to gratify curiosity and to raise wonder; it ought to beget profound submission, and pious trust in every heart.
Histories of the providence and caution, the care and foresight of the most inconsiderable among animal beings, must surely ever be read with pleasure and attention, as conveying a most beautiful lesson to a reflecting mind; it is impossible for any one thus instructed to think that the Great Being, who has been so careful of those inferior creatures, can be regardless of him whom he has placed in a station infinitely more exalted. Throughout the whole system of things, we behold a manifest tendency to promote the benefit either of the rational or the animal creation. In some parts of nature, this tendency may be less obvious than in others. Objects, which to us seem useless or hurtful, may sometimes occur; and strange it were, if in so vast and complicated a system, difficulties of this kind should not occasionally present themselves to beings, whose views are so narrow and limited as ours. It is well known, that in proportion as the knowledge of nature has increased among men, these difficulties have diminished. Satisfactory accounts have been given of many perplexing appearances; useful and proper purposes have been found to be promoted by objects which were at first thought to be unprofitable or noxious.[47]
[47] The great beauty of the dye produced by the cochineal insect, and
the medical virtues of the cantharis, have occasioned them to be
considered as very extensive and valuable articles of commerce. The
benefits derived from the bee and the silk-worm are universally known;
and spiders, could a method be devised to induce them to live in
harmony, might also be productive of very essential advantages to the
human race. EDIT.
Malignant must be the mind of that person; with a distorted eye he must have contemplated creation, who can suspect that it is not the production of infinite benignity and goodness. How many clear marks of benevolent intention appear every where around us? What a profusion of beauty and ornament is poured forth on the face of nature? What a magnificent spectacle presented to the view of man? What a supply contrived for his wants? What a variety of objects set before him, to gratify his senses, to employ his understanding, to entertain his imagination, to cheer and gladden his heart? Indeed the very existence of the universe is a standing memorial of the goodness of the Creator; for nothing except goodness could originally prompt creation. No new accession of felicity or glory was to result to him from creatures whom he made: it was goodness communicating and pouring itself forth, goodness delighting to impart happiness in all its forms, which in the beginning created the heaven and the earth. Hence those innumerable orders of living creatures with which the earth is peopled, from the lowest class of sensitive being to the highest rank of reason and intelligence. Wherever there is life, there is some degree of happiness; there are enjoyments suited to the different powers of feeling; and earth, air, and water, are with magnificent liberality made to teem with life.[48]
[48] Blair’s Sermons.
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Essays on the MicroscopeChapter L: M N is a guide for the eye, in order to direct it in the axis of the (4)
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