a circle in the government of Stettin and the Prussian province of Pomerania. It extends over 566 square miles, or 368,240 English acres. There are within it 4 cities, 6 towns, and 201 villages. The inhabitants are 30,856. The land is a plain, with extensive woods, and about twenty fresh-water lakes, the largest of which is the Althbeckr. The feeding of cattle and growing of corn are the chief objects of agriculture; besides which, some hops and tobacco, and much flax, are grown. The woods afford much profitable employment, and furnish charcoal to the iron-works in Pomerania. The capital of the circle is of the same name. It is situated on the river Peene, and is now without fortifications. It contains 3 churches, 3 hospitals, 599 houses, and 5833 inhabitants. By means of the river, which is navigable, it carries on some trade; and it has manufactures of cloth, hosiery, tobacco, snuff, and leather. It is in long. 24. 1. 59. E. lat. 53. 49. 15. N.
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The following summary from the pen of Mr Brown contains the renewed expression of that gentleman's opinion, matured by the recent experiments on the subject of active molecules. "That extremely minute particles of solid matter, whether obtained from organic or inorganic substances, when suspended in pure water or in some other aqueous fluids, exhibit motions for which I am unable to account, and which, from their irregularity and seeming independence, resemble in a remarkable degree the less rapid motions of some of the simplest animalcules of infusions. That the smallest moving particles observed, and which I have termed Active Molecules, appear to be spherical, or nearly so, and to be between \( \frac{1}{1000} \) th and \( \frac{1}{2000} \) th of an inch in diameter; and that other articles of considerably greater size, various sizes, and of very similar or even different figures, also present analogous motions in like circumstances. I have formerly stated my belief that these motions of the particles neither arose from currents in the fluid containing them, nor depended on that intestine motion which may be supposed to accompany its evaporation. These causes of motion, however, either singly or combined with others,—as the attractions and repulsions among the particles themselves, their instable equilibrium in the fluid in which they are suspended, their hygrometrical or capillary action, and in some cases the disengagement of volatile matter, or of minute air-bubbles,—have been considered by several writers as sufficiently accounting for the appearances. Some of the alleged causes here stated, with others which I have considered it unnecessary to mention, are not likely to be overlooked, or to deceive observers of any experience in microscopical researches; and the insufficiency of those enumerated may, I think, be satisfactorily shown by means of a very simple experiment. This experiment consists in reducing the drop of water containing the particles to microscopic minuteness, and prolonging its existence by immersing it in a transparent fluid of inferior specific gravity, with which it is not miscible, and in which evaporation is extremely slow. If to almond oil, which is a fluid having these properties, a considerably smaller proportion of water, duly imprengated with particles, be added, and the two fluids shaken or triturated together, drops of water of various sizes, from \( \frac{1}{1000} \) th to \( \frac{1}{2000} \) th of an inch in diameter, will be immediately produced. Of these, the most minute necessarily contain but few particles, and some may be occasionally observed with one particle only. In this manner minute drops, which, if exposed to the air, would be dissipated in less than a minute, may be retained for more than an hour. But in all the drops thus formed and protected, the motion of the particles takes place with undiminished activity, while the principal causes assigned for that motion, namely, evaporation and their mutual attraction and repulsion, are either materially reduced or absolutely null."