mon green ribbon, the yellow, the light red and a blue, appeared distinct and very plain; the lively green was a yellow and blue: in a sea green, more blue than yellow: the yellow was a light red and a pellucid white. All the phoenomena of colours were here to be found out.

In this instrument, the finest point of a needle appeared more blunt and unequal, and more like a broken nail, than I had before seen it. The finest, edge of a razor was like the back of a dog, with the hair up. The finest paper, was great hairs, cavities, and unevenness, and the smoothest plate of glass, was very rough, full of cracks, fissures and inequalities. Very different, indeed, are the things finished by human art from the things finished by the hand of nature. The points, the edges, the polish, the angles, every thing that nature produces, appear in the instrument in a perfection that astonishes the beholder.

In the views I here took of the vegetable world, with my eye thus armed, I saw many extraordinary things I had never observed before. I took notice, in particular, that a sage leaf is covered with a kind of cobweb, in which swarms of little active creatures, with terrible horns and piercing eyes, are busily employed: a mulberry leaf was an amazing flexus or net-work: we can see but nine ribs on the sigillum Solomonis; whereas my armed eye perceived here

seventy-four: in a nettle I observed its whole surface covered over with needles of the most perfect polish, every one of which had three points, points very different from our finest points, not flat, but to perfection sharp; and that these needles rested on a base, which was a bag of a flexible substance, in form of a wild cucumber, and filled with a sharp, poisonous liquor this is discharged at the extremity of every point of the needles that cover the surface of the nettle from a hole visible in every point the poison is thrown out, and excites a sense of pain; and a heat arises as the blood flows more copiously to the wounded part. By pressing with my finger the extremity of the prickles, the bag of poison fell; and on taking off the finger, it swelled again. What a piece of workmanship is here in a nettle! Wonderful are thy works, O Lord God Almighty!

A leaf of sorrel in this microscope exhibited to my eye oblong, rough and straight atoms, sharp as needles, and from thence the tongue is twinged. In a bud cut away with a fine needle from a steeped seed of a French-bean, I saw the entire plant; and in an almond so cut away, the perfect tree. Many other wonderful things I observed of the vegetable kingdom, in the microscopes of these gentlemen.

As to the animal kingdom, my observations on it, in the optical instruments at Ulubræ, were so

many, that I could fill a volume with the things I saw: but, as I have little room or time to spare, I shall only mention two or three. In the double reflecting telescope, a louse and a flea were put; which are creatures that hate each other as much as spiders do, and fight to death when they meet. The flea appeared first in the box, and as he was magnified very greatly, he looked like a locust without wings; with a roundish body, that is obtuse at the end, and the breast covered with an armature of a triangular figure; the head small in proportion to its body, but the eyes large, red, and very fierce; his six legs were long, robust and made for leaping; the antennæ short, but firm and sharp; its tail was scaly, and full of stings, and its mouth pointed into active pincers his colour was a deep purple.

The louse in white was next brought on, and had a well shaped, oblong indented body: his six legs were short, made for walking and running, and each of them armed at the extremity with two terrible claws the head was large, and the eyes very small and black: its horns were short and jointed, and could be thrust forward with a spring. Its snout was pointed, and opened, contracted, and penetrated, in a wonderful manner.

The first that was brought on the stage was the flea, and to shew us what an active one he was, he

sprung and bounced at a strange rate: the velocity of his motions in leaping were astonishing; and sometimes, he would tumble over and over in a wanton way but the moment the louse appeared, he stood stock still, gathered himself up, and fixed his flashing eyes on his foe. The gallant louse did with a frown for sometime behold him, and then crouching down, began very softly to move towards him, when the flea gave a leap on his enemy, and with his dangerous tail and pinching mouth, began the battle with great fury; but the louse soon made him quit his hold, by hurting him with his claws, and wounding him with his sharp snout. This made the flea skip to the other side of the box, and they both kept at a distance for near a minute, looking with great indignation at each other, and offering several times to advance. The louse did it at last in a race, and then the flea flew at him, which produced a battle as terrible as ever was fought by two wild beasts. Every part of their bodies was in a most violent motion, and sometimes the flea was uppermost, but more frequently the louse. They did bite, and thrust, and claw one another most furiously, and the consequence of the dreadful engagement was, that the flea expired, and the louse remained victor in the box: but he was so much wounded, that he could scarce walk. This battle

was to me a very surprising thing, as each of them was magnified to the size of two feet: but considering what specs or atoms of animated matter they were, it was astonishing to reflection to behold the amazing mechanism of these two minute things, which appeared in their exertions during the fray. It was still more strange to see the aversion these small creatures had to each other, the passions that worked in their little breasts, and the judgment they shewed in their endeavours to destroy one another. It is indeed a wonderful affair: nor was it the least part of admiration to see through the extraordinary transparencies of the louse, the violent circulation of the blood in its heart. This was as plain to my eye, as red liquor forced by a pump in several experiments through circulating glass pipes. As to the dead flea it was opened, and by the camera obscura or solar microscope, which magnifies the picture of such a body as a flea, to eight feet*; we saw the

* Though the image of a flea may be magnified to eight feet, by removing farther off the white paper screen, on which the picture of the object is thrown very beautifully from the object posited in a single pocket microscope that is fastened to a tube to the solar microscope; yet the image or picture is more distinct and exact, when not enlarged to more than three feet, on the opposite side of the darkened room. By the way, reader,