so extremely minute that 200 of them "may be covered by a common grain of sand," they are disposed with great regularity, and are of a pentagonal figure. It would seem that the skin has no proper pores, except such as exist in the interstices of these scales. The author thinks that their number is the same at all ages, and that therefore, as the body increases in size, each individual scale must grow proportionably. We have next some observations on gouty and urinary concretions, and on the nature of gunpowder; subjects on which the author's knowledge was necessarily very deficient; and we afterward come to a train of microscopical experiments on the louse, which, were it not for the disgust excited by the object, we should rank among the most attractive parts of the volume. We shall only notice one fact, which the writer seems to have discovered, that the sensation of itching, produced by these animals, is not caused by their bite, but by a sting which the male protrudes from the extremity of its body.

M. Leeuwenhoek's next investigations relate to some of the most minute animals that are perceptible to the naked eye, viz. the mite, the different kinds of insects which injure fruit-trees, and the animalcules that are found in the sediment of water. To the subsequent paper, which gives an account of the circulation of the blood in the tail of the eel, the translator subjoins a description of the microscopes which were employed, taken from the writings of Mr. Baker. In the next essay, on frogs, and on the manner in which they are produced from tadpoles, we have a number of additional observations on the globules of the blood, especially respecting their shape and size:

"In my several observations on the circulation of the blood in fishes, I have not been able clearly to satisfy myself with

regard to the shape of the globules or component particles of the blood, for they sometimes appeared of a spherical, and sometimes of an oval and even a flat shape, and sometimes an irregular figure; this I sometimes attributed to my glasses not being of sufficient magnifying power to distinguish them, and sometimes to the position in which they appeared to the eye, for, while in circulation, they tumbled one over another, sometimes presenting one part and sometimes another to the view; and I also thought that it might be owing to the straightness of the vessels, in which the particles of blood, being of a yielding nature, might, by the compres sion, lose their spherical figure.

"In order to satisfy myself in some degree on this head, I cut off pieces from the tails of several small, flat fish, such as plaice and flounders, in order to view the blood when drawn out of the vessels, and the rather, because I could not persuade myself, that the natural shape of the par

ticles of blood in fishes was an oval; forasmuch, as a spherica! seemed to me to be the more perfect form. For I was of opis. nion, that the particles of blood in fishes were composed of six globules, in like manner with the blood in man, and in terrestrial animals: and I several times saw the particles of fishes' blood, the original texture of which was broken, and in which I could distinctly see four or five, and in some few of them six component particles. I, however, thought it worthy of note, that many of these particles of blood appeared to me of an oval shape, some few others roundish, and others of a perfect spherical figure.

In order farther to prosecute my inquiries on this subject, I took the blood of a salmon not quite dead, which was received into a glass tube, about the size of a small writing pen: this blood, after a ving restored it in part to its fluidity, I put short time, became coagulated; but ha it into a smaller glass tube, in which I viewed it, holding it so, that the particles of blood might be kept in motion continually, by which means many of the particles appeared before my sight with a flat and oval shape; in others, the sides of which were turned towards me, I could scarcely perceive any sensible thickness; and in short, others, where their sides were not exactly turned towards me, appeared some what broader in proportion to their size; but I could not discover one particle of blood of a perfect spherical shape."

We have quoted this description

at length, because it is a subject which has given rise to much controversy, and the passage must impress the reader with a favourable opinion of the author's candour. Apparently, he could scarcely be deceived respecting the shape of the globules, although we do not assent to his theory of their composition.

We now come to some remarks on phosphorus, and on the sting of the gnat; experiments on insensible perspiration; observations on the common fly, and on the eggs of the shrimp; essay on the salts contained in pepper, tea, and cantharides; on the embryo plant discoverable in seeds and buds; and on the structure of the nerves. The observations on the nerves are very curious; and had they obtained more general attention, they might, perhaps, have prevented the appearance of some of those idle hypotheses which have been formed respecting the origin of the sensations. The author speaks of the nerves as being "composed of very minute vessels of an incredible thinness, which, running by the sides of each other, constitute a nerve." As to the size of them, the vessels are described as being so small, that "some hundreds of them go to the composition of a nerve no larger than the hair of a man's beard; and although (says the writer) these cavities, or the orifices of these vessels, are so wonderfully minute, I have seen living creatures in the waters, which could have moved and swam about in them with freedom." We are informed that the author, at the time when he made these minute observations, was not less than eighty five years

of age.

A paper succeeds on the quantity of air contained in water and other fluids; and afterward a description of an ingenious contrivance for illustrating the effect which the earth's motion about its axis must have on the atmosphere. It is supposed that the centrifugal force will throw off the clouds from the cen

tre, and thus support them at some distance from the earth's surface. In some remarks on the circulation of the blood, the principal object is to show that the circuit must be complete in different times, according to the distance of the parts from the heart. By comparing together the observations which he has made on various subjects, the author concludes that the blood circulates through the tail of the eel thirteen times in an hour, while in the upper parts of the body it will circulate ninety six times. Provided that the blood in the human body moves at the same rate as in the eel, it will pass through the lower extremities only between two and three times in an hour, through the upper extremities above four times; and through the head eight times: but, in an hour, as much blood will pass through the heart as is equal to fourteen times the quantity contained in the whole body. The proportions of these numbers may probably be correct, but we think that the whole estimate is considerably too low. With some remarks on the nature of lime, on wood that has been worm-eaten, and on the eyes of fish, the volume concludes.

The estimate of Leeuwenhoek's merits as a naturalist must be considerably raised in the minds of those who peruse these volumes; and who, though they may have frequently heard him quoted, or have occasionally examined some parts of his works, had not before so fully conceived the extent of his labours, His writings have certainly been too much neglected, and therefore we cannot but express our obligation to Mr. Hoole for putting them in so commodious a form, in a translation which seems to be well executed; and we must not omit to render a due tribute of applause to the excellence of the engravings. The notes, which are occasionally added, do not, in our opinion, increase the value of the work: but they are not very numerous.

and the subject of this biographical memoir, by means of a common friend. And it appears evident, that it was the decided opinion of the former, that the latter should be restored to his country. During this negotiation, in the course of which, the ex-secretary refused to disclose any intelligence that might affect his credit or wound his honour, the earl of Oxford, who had been committed so long to the tower, was brought before the house of peers, and acquitted, in consequence of a dispute with the commons.

Notwithstanding this, his colleague still remained in a foreign land. The urbanity and gayety of the French nation appeared to be very suitable to his disposition; he was accustomed to deem himself "the least unfortunate of exiles;" He possessed a sufficiency of money to live in a handsome style; and his company was eagerly solicited by all the men of talents in France. In 1717, he formed an acquaintance with the marchioness de Villette whose maiden name was Maria Claire Deschamps de Marcilly, and who had been married to the marquis Villette Mursay, a relation of madame de Maintenon. She was then a widow with several children, had been educated at St. Cyr, and lived in the faubourg Saint Germain. This lady was about fifty-two years of age, possessed a very considerable fortune, and at the same time had a number of law-suits." Without being handsome, she knew how to please. She possessed wit, and might be said to have conversed with great effect, provided she had spoken but a little less." Bolingbroke soon felt himself in love with her; and as she was pleased with him, a close and intimate friendship immediately commenced, which was, however, frequently interrupted and embittered. by his jealousy.

Imagining one day, at dinner, that she had a liking for Mr. Macdonald, first esquire to the pretender, and a

very handsome man, he overturned the table in a fury, and broke all the glasses. The abbé Alari, who was a witness to this scene, was ac customed to observe, in addition; "that in 1715, Madame de Villette had intrusted him to carry to the count de Boulainvilliers, who piqued himself on drawing horo-copes, the date of her birth, and a variety of other particulars, for his opinion." The answer was, "that the lady was affected by a great number of passions; that she would experience one stronger than all the rest at the age of fifty-two, and at length die in a foreign country." All this prophecy," adds the editor, "was afterwards fully realized; and yet no reliance whatsoever ought to be placed on the skill of the fortuneteller, who was completely deceived in respect to the predictions made by him in respect to himself.

At length, after a variety of lapses, lord Bolingbroke concentrated his passion for the whole sex in Madame de Villette alone, and his own lady, who had turned devotee, having died in November, 1718, the publick conduct of the two lovers from that moment became less em barrassing. He first accompanied this lady to her estate at Marcilly, near Nogent sur Seine, and afterwards conducted her to the waters of Aix-la-Chapelle, where it was generally believed that they were married in May, 1720. It was also asserted, that Madame de Villette, at the same time, abjured the catholick religion: but the abbe Alari, and all those intimate in the family, were fully persuaded that no abju. ration had taken place, and that no marriage had ever been completed. It was convenient, however, to keep up appearances, although they never avowed their union until the month of July, 1722.

The viscount loved the country, and Marcilly would have proved a most agreeable residence; yet in 1719, he purchased the little estate of la Source, near Orleans, and con

verted it into an enchanting abode. There he spent many happy days in the arms of philosophy, the muses, and voluptuousness, assigning to his pleasures that portion of time which he had never refused them, reserving for study the hours formerly devoted to business; and reuniting around him a society selected from men of letters, men of the world, and the most amiable of the other sex. Voltaire, who formed one of the party, declares he was enchanted with his visits. "I have found," said he, "in this illustrious Englishman, all the irrudition of his country, mingled with all the politeness of our own. I never heard any one pronounce our language with more energy and propriety. This man, who has been all his life engaged in pleasures and business, has, nevertheless, found means to learn, and to retain every thing. He is as well acquainted with the history of the Egyptians as of the English. He is equally familiar with Virgil and Milton; and he loves French, Italian, and English poetry; but he loves them differently, because he perfectly discerns the different genius of each."

Meanwhile, the mind of viscount Bolingbroke was continually busied about the means of returning to his native country. The earl of Stanhope, one of his most bitter enemies, was now dead [1721] but sir Robert Walpole was still in credit; the earl of Sunderland and the duke of Marlborough, who were his friends, did not long survive; while the dutchess dowager, who professed a particular esteem for the man, "who alone, was worthy to praise her husband," no longer enjoyed any credit.

As means were about to be recurred to in London, for repealing the bill of attainder, Madame de Villette was sent thither, and, under the name of lady Bolingbroke, acted in concert with lord Harcourt. All their solicitations, however, would have proved ineffectual, but for the patronage of the dutchess of Kendal,

who is said to have sold his lordship's pardon at an enormous price! Be this as it may, he arrived at Calais on the 11th of May, 1723; four days after it had passed the great seal: but on learning that it extended only to his life, and that he was deprived of the peerage and his estates, he immediately repaired to Aix-la-Chapelle

In 1725, lord Bolingbroke at length revisited his native country; and an act of parliament was soon after passed for the purpose of re storing his property to him; but the enmity, and it has been added, the jealousy of Walpole, prevented the restoration of his dignities. The conduct of the minister on this occasion excited the bitterest animosity on the part of Bolingbroke, who soon became one of the most violent, as well as most formidable, of his political foes. As his father was still alive. and in possession of the principal estates, the viscount resolved to settle at "Dawley," near Uxbridge, and there resigned himself to the enjoyment of country amusements, and the company of the learned, such as Swift and Pope. He also connected himself openly with the opposition, and published many able letters in the Craftsman, besides a variety of pamphlets, which occasioned a great sensation. On the demise of George I it was supposed that a change in the administration would have taken place; but Walpole was enabled to obtain a greater share of credit under that than the preceding reign. The viscount, who was not discouraged by this unexpected circumstance, immediately formed a strict union with Willlam Pulteney, afterwards earl of Bath, and then at the head of a most powerful party.

Notwithstanding this, in 1735 he returned to France, and as he had sold the estate of la Source, he now hired the castle of Chanteloup, which was afterwards embellished by the celebrated duke de Choiseul, while an exile like himself. Here,