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calculations necessary to determine facts, and yet stop short of the reflections so natural upon making the dis covery, and for the sake of which alone, one would think it was worth while to have bestowed the pains. For it is really of very little consequence to us to know the exact proportion between the magnitude of a grain of sand and an animalcule in pepper-water; the wonderful regularity of the motions of all the great bodies in nature, describing equal areas in equal times; the amazing properties of light and colours; and the means by which vision is performed, and the like: it is, I say, of very little consequence to know a number of facts which obtain in nature, if we never consider them farther than as dry uninteresting facts, nor think of applying our knowledge of them to some purpose of usefulness for life or futurity.

The invitations to acquire a general knowledge of anatomy are innumerable. An animal body is indeed a system of miracles. The number of various parts adapted to such various uses; the structure of the bones, as the supporters of the whole frame; the number and apt inser. tion of the muscles, for performing the various motions of the body with ease and gracefulness; the endless variety of vessels, tubes and strainers, gradually lessening to imperceptibility, with the fluids circulating through them, and, secreted by them, for the various purposes of nature, which render the body of an animal a system in which a greater number of streams are continually flowing, than those which water the largest kingdoms upon earth, or, more probably, than all that run in all the channels round the globe.

The eye alone, that miracle of nature, is a study for life! We find how difficult it is to form and adjust a set of glasses for any compound optical instrument. Yet glass is a solid substance, which will keep the form that is once given it. But the eye must be considered as a composition of various coats or pellicles, of three different humours and a set of muscles, to alter the form of those humours, and the aperture of the eye, instantaneously, according to the situation, or distance, brightness or obscurity, of the object to be viewed; at the same time, that the whole mass of the eye is to be considered as a system in which there are innumerable streams continually flowing. Now

as we know, that in order to distinct vision, the laws of optics require the figure of the eye to be strictly true and regular; that it should continue fit for vision for a few moments together, considering of what soft and pliable substance it is made, and how continually changing its figure and state, is what we can in no respect give an account of. How delightful is the search into these wonders! How naturally does it lead the well disposed mind to love and adore the Almighty Author of so excellent a work!

There is indeed none of the works of nature, down to the most common and contemptible (if any thing could be so called, which infinite Wisdom has deigned to make) that is not found, when attentively examined, to be, for curoisity of structure, above the apprehension of any human mind. What is meaner, or more common than a pile of grass? Yet, whoever with a miscroscope, examines its various parts, will find it a work of such curiosity, as to deserve his highest admiration. In the blade he will find a double coat throughout, between which, the vessels which convey the juices to nourish it, are disposed. The minuteness of those tubes decreases to imperceptibility. Nor do the same vessels carry and return the juices. There are in every plant, and consequently in every pile of grass, two kinds of vessels, analogous to the veins and arteries in an animal body, by means of which a circulation of the juices is performed. The blade is also furnished with excretory vessels to carry off by perspiration whatever juices may be taken into the plant, which may be super. fluous, or unfit for its nourishment, and with absorbent vessels, at whose orifices nourishment is taken in from the ambient air, as well as from the earth by the root. The blade is always furnished with a strong fibrous substance running up its middle, and tapering to a point, for supporting and strengthening it. The substance of the roots of all plants, is quite different from the other parts, in outward form and internal structure. It is so in grass.. Every single tendril is furnished with vessels, at whose open mouths the proper juices enter, which, as they mount upwards, are secreted, so that those which are proper for each respective part, are conveyed to it; and the other particles, by means of valves and other contrivances within the vessels, are stopped and turned back. The substance

of the root itself is of three sorts, the cortical, or bark, the woody part, and the pith. Each of these has its vessels or passages, differently disposed, and of a different size and make, as the microscope shows. The seed itself is a miracle of curiosity. For in every single grain the stamina of the future plant, or rather of the plant itself in miniature, is disposed so that the growth of the plant is only the unfolding of the stamina, and their enlargement by the addition of new juices. If the opinion of some naturalists be well founded, viz. that in the stamina contained in a seed, there are also contained the stamina of the plant which is afterwards to spring from that, and so on for ever, this increases the wonder infinitely. It is likewise observed, that almost every plant, if cut off above the root, will send out new branches, leaves, and seeds almost endlessly. So that it would seem, that every stock of every plant, and consequently every stalk of grass, as well as every seed, contained almost an infinite number of other plants, branches, leaves, and so forth, in miniature. But I will not urge this too far, because there is another hypothesis, which does not require such inconceivable minuteness of stamina, nor their being thus disposed one with. in another, without end, from the creation of the first plant : I mean, the supposition of those stamina floating in the air, in infinite numbers, and being received into proper matrices, and so fructifying. Be this as it will, there are, as we have seen, wonders without end in so despicable an object as a pile of grass. After all that has been said, there may, for any thing we know, be a thousand times more unknown of the internal substance or structure of a pile of grass. We know not how two particles of matter come to adhere to one another, why they do not fall asunder like grains of dust or sand. We know not how the particles of nourishment are taken into the vessels of the root of a plant; how they are carried on and secreted every one to its proper place; what it is in the make of the particles of the juice, and effluvia exhaled from the root and blade, which makes them taste or smell differently; what disposition of the external parts makes the root part appear white, and the blade green, and so on. Yet this subject,. in which there are so many curiosities known to us, and enough of inexplicable difficulties to puzzle all the philoso

phers of ancient and modern times is no rarity, but it is every where to be met with. The whole earth is covered with it. Whilst every single pile, of which there may be some thousands in every square foot of ground, is formed with all the admirable curiosity and exactness I have been here describing. What then is the art displayed in all the various and numberless plants of different species which cover the face of the earth? What the profusion of workmanship in the innumerable multitudes of beasts, birds, fishes, and insects, which inhabit all parts of the earth and waters; of which every single individual displays wonders of inexpressible power and inconceivable wisdom bevond number? "Great and manifold are the works, O Lord, in wisdom hast thou made them all."

If a person has a strong genius for mathematical learning, it will be natural for him to improve himself in the higher parts of that noble science, as plain and spherical trigonometry, conic sections and fluxions. But it does not appear to me absolutely necessary to the idea of a well improved mind, that a person be master of those abstruse parts of mathematics. On the contrary, I know not whether the employing a great deal of time in those parts of science, which are rather sublime and curious, than useful in life, can be justified; at least, where a person has a capacity for improving himself and others in useful knowledge. On the other hand, it must be owned, that the exercising the genius in the most difficult parts of study, is not without its uses, as it tends to whet the capa eity, and sharpen the faculties of the mind, which may, for any thing we know, be of advantage to it, in fitting it for the sublime enjoyments of a future state. Add to this, that it is not always easy to say what is altogether useless in science. What has been at its first discovery looked upon as a mere curiosity, has often been found af terwards capable of being applied to the noblest uses in science, and in life. This has been experienced in no instance more frequently than in the discovery of mathematical proportions. Those of triangles were discovered before they were found to be of such important usefulness in mensuration and navigation; and those in common geometry, in trigonometry, conics, and fluxions, before they were applied to astronomical calculations. Nor

can any one pronounce with certainty, that those which have not yet been applied to any direct use for improving science, or art, never will, or are capable of it. Upon the whole, the pursuit of any study, however it may seem merely curious, rather than useful, is an employment incomparably more noble and suitable to the dignity of human life, than those of pleasure, power, or riches. Though this is not saying, that study is the sole business of life, or that it may not be carried lengths inconsistent with our present state.

For improvement in the higher mathematics, Wolfius' and Wilson's Trigonometry, Muller's or De la Hire's Conic sections, Ditton's, Simpson's, or Maclaurin's Fluxions may be studied.

At last we come to the summit and pinnacle of knowledge, the utmost reach of human capacity, I mean the Newtonian philosophy. This sublime of science is what very few, perhaps not six in an age, have been found equal to. The labours of that prodigy of our species; the calculations and demonstrations upon which he has founded his immortal and impregnable structure, are not to be investigated, but by one possessed of the quickest penetration, the most indefatigable diligence, leisure, and vacancy of mind. There are, for example, some of his problems, which few men can hold out to go through; few minds being capable of keeping on the stretch for so long a time as is necessary for the purpose. It will therefore be in vain to advise readers in general to try their strength in this Achillean bow. It is however, possible to acquire a general idea of his philosophy from Pemberton's and Maclaurin's views of it. They who would go farther, must read his Principia with the Jesuit's Comment, and his Optics.

I will here give a list of books which will make a pretty complete and useful collection upon the various branches of natural philosophy and mixt mathematics. Ray's Wisdom of God in the creation. Derham's Physio-thcology. Nature displayed. Nieuwertyt's Religious Philosopher. Bacon's and Boyle's Works. Lieuwenhowek's Arcana. Adams' Micrographia, and Baker's Employment for the Microscope. Ray's, Ruysch's and Gesner's History of Animals. Willoghbuy's Ornithologia. Swam