way, I looked over in the journal of these gentlemen. I likewise saw them perform several extraordinary experiments.

They make all the mathematical instruments they use, and have brought the microscope in particular, to greater perfection than I have elsewhere seen it. They have them of all kinds, of one and more hemispherules, and from the invented spherule of Cardinal de Medicis, not exceeding the smallest pearl placed in a tube, to the largest that can be used. They had improved the double reflecting microscope, much farther than Marshal's is by Culpepper and Scarlet, and made several good alterations in the solar or camera obscura microscope; and in the catoptric microscope, which is made on the model of the Newtonian telescope.


In one of their best double reflecting optical instruments, I had a better view of the variety and true mixture of colours than ever I saw before. The origins and mixtures were finely visible. In a common 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 inequalities—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 9 ribs on the sigillum Solomonis; whereas my armed eye perceived here 74: 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