An Account of Some Remarkable Insects of the Polype Kind, Found in the Waters Near Brussels in Flanders. In a Letter to Thomas Birch, D. D. Secret. R. S. from T. Brady, M. D. Physician to His Highness Prince Charles of Lorraine

been dead many hours; and the farmer assured me, that they always found these worms in this distemper, and knew of no method of cure. I should have great hopes however, that fumigations, either with mercurials, as cinnabar, or with fatids, as tobacco, properly used, might prove of great service. You have herewith the two species of worms, (See Plate VII. Fig.1.*) in order to be lodged in the repository of the Society, if it be judged requisite. I am, Sir, with the greatest respect to you, and the Society, Lincoln's-Inn-Fields, Nov. 6, 1755. Your most humble servant, Frank. Nicholls. XL. An Account of some remarkable Insects of the Polype kind, found in the Waters near Brussels in Flanders. In a Letter to Thomas Birch, D. D. Secret. R. S. from T. Brady, M. D. Physician to his Highness Prince Charles of Lorraine. SIR, Read Nov. 6, 1755. THE plant, of which I send you the inclosed draught, is found in summer-time, in all sorts of ditch or stagnant waters: its colour is white, and its transparent body, when seen with the naked eye, is in length betwixt one and and an half and two lines, but when view'd with a good microscope, whose focus is about eight lines, it appears as you see in Plate VII. Fig. 1. with leaves, branches, and fruit, and indued with such sensibility, that at the least noise made in the room, or upon any thing's touching the table where your microscope stands, or the water in which it lies, it contracts itself with such activity and swiftness, that the eye cannot follow it in that motion, till it reduces itself into the shape you see it twisted in Fig. 2. The extension or dilation goes slower, and requires about half a minute before it comes to the form you see it in, like a grape, in Fig. 5. It can live in its own standing-water for eight or ten days, and then looks as you see it in Fig. 6. as most trees do in winter-time. It is remarkable, that the leaves, which are like bells, live some time after they fall, and retain that faculty of contraction and dilatation; and when you view them with our great magnifier, whose focus is about two lines, it appears as in Fig. 4. The trunk is as you see it in Fig. 3. The number of its branches are undetermined, but commonly found to be betwixt six and twelve. We have not tried, if it does not regenerate, when cut, like polypes: But one can see a vast difference betwixt it and the Polype à bouquet, of which Mr. Trembley makes mention. The other curious insect represented in Fig. 1. is found in the same standing-waters with the plant, and is seen with the naked eye, like a little flat round leaf, whose diameter is about one line and an half; but when put in a microscope, it shews a circle surrounded with crown'd heads, tied by small thin tails to a common centre, from whence they advance towards the circumference, where they turn like a wheel, with a great deal of vivacity and swiftness, till they cause a kind of a vortex, into which you will see all smaller insects or bodies either attracted or driven, which probably serve as nourishment for those little crown'd things, who in all appearance are, as well as the plant, a sort of insects of prey, that live on smaller creatures. When one of those little heads has wheel'd a while, it rests, and another turns out; and sometimes you will see three or four wheeling at a time. We have seen last year some much more regular, that formed an orderly circle, with their crowns to the circumference, and their thin bodies like so many radius's join'd to the centre. Their motion is all strait towards the edge of the circle, and never to the right and left, as if every head had its proper limits to act upon. One Symoy, an optique instrument-maker, found the first of those insects as he was searching for polypes; which gave me since an occasion of examining ditch-water, where I not only found the plant, but the crown'd insect, and a good many other surprising little things, of all shapes and fashions, of which I will take the liberty to send you an account. Mr. Mitchell, the British minister for the congress at Brussels, saw those curious insects, and observed, which we did not take notice of before, that the fruit of the plant, which resembles an orange, has a kind of a chain about it, that turns as the crown does in the other insect. He took notice also, that the trunk or stock of the plant was its gut, or stomach; for he saw, that something descended through it, as it were were through a gut. Besides it has no support of any fix'd point, but is always swimming in the ditch-water, and shews no great local motion. We saw other insects preying upon it, which resemble small hogs, and are excessive busy in eating of its leaves, which are probably the cause of its looking so bleak and withered when dead. I remain, SIR, Your most humble Brussels, Sept. 20, 1755. and obedient servant, T. Brady. XLI. A short Account of some new Astronomical and Physical Observations made in Asia; and communicated to Matthew Maty, M.D. F.R.S. by his Excellency Mr. Porter, his Majesty's Ambassador at Constantinople, and F.R.S. Constantinople, May 17, 1755. Read Nov. 6, 1755. I send you inclosed the extract of a French letter I received from a person of great abilities, whose history I cannot immediately communicate to you. It was sent me by the consul of Aleppo. The author is perfectly versed in most branches of physics, as well as in the art of healing. Kk2 Extract