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XLVII. Intelligence and Miscellaneous Articles, 



brown's microscopical observations on the particles 

 of bodies.* 



MUNCKE, of Heidelberg, finds the following a simple and easy 

 mode of showing the motions of particles : — Triturate a piece of 

 gamboge, the size of a pin's head, in a large drop of water on a glass 

 plate; take as much of this solution as will hang on the head of a pin, 

 dilute it again with a drop of water, and then bring under the micro- 

 scope as much as amounts to half a millet-seed : there are then obser- 

 vable in the fluid small brownish yellow, generally round (but also of 

 other forms) points, of the size of a small grain of gunpowder, in 

 distances from one another of 025 to 1 line. These points are in 

 perpetual slower or quicker motion, so that they move through an 

 apparent space of I line, in from 0*5 to 2 or 4 seconds. If fine oil of 

 almonds be employed in place of water, no motion of the particles 

 takes place, while in spirit of wine it is so rapid as scarcely to be 

 followed by the eye. This motion certainly bears some resemblance 

 to that observed in infusory animals, but the latter show more of 

 voluntary action. The idea of vitality is quite out of the question. 

 On the contrary, the motions may be viewed as of a mechanical na- 

 ture, caused by the unequal temperature of the strongly illuminated 

 water, its evaporation, currents of air, and heated currents, &c. If 

 the diameter of a drop is placed at 0*5 of a line, we obtain, by magni- 

 fying it 500 times, an apparent mass of water of more than a foot and 

 a half the side, with small particles swimming in it ; and if we consi- 

 der their motions magnified to an equal degree, the phenomenon 

 ceases to be wonderful, without, however, losing anything of its in- 

 terest. — Jameson's Journal, Julv 1830. 



VEGETABLE MILK OF THE HYA-HYA TREE OF DEMERARA. 

 Dr. Christison has lately analysed this substance. Its principal 

 properties are the following : In the state in which it arrived in this 

 country, it consisted of a small portion of a clear watery-like fluid, 

 and a white concrete, cellulated substance, not unlike pressed curd, 

 which filled nearly the whole bottle. It had an odour somewhat like 

 that of cheese, with a slight peculiar aroma and scarcely any taste ; 

 the watery portion appears to contain a little acetic acid. The con- 

 crete matter is of snowy whiteness, brittle and pulverizable when cold, 

 but easily softened by an increase of temperature. At 100° Fahr. it 

 becomes ductile and viscid, and does not recover its original firmness 

 and hardness for more than a day. At high temperatures it becomes 

 more fluid, the vapour is combustible with much flame and smoke. 

 Water cold or boiling has no action on this substance ; heated alco- 

 hol acts slightly on it. Sulphuric aether dissolves it rapidly, leaving 

 only four per cent, of a soft viscid mass. 



From the preceding and other experiments, Dr. Christison con- 

 cludes that the juice of the hya-hya tree consists of a small portion 



* See Phil. Mag. and Annals, N.S. vol. iv. p. 161. vol. vi. p. 161. 



of 



