184 Scientific Jnlelligxncc. — Chemistry. 



an uncombined state. The truth is, we have not hitherto dis- 

 covered the cause of the colour of ice and water. — Karsteii^s 

 Archiv. b. xviii. 



3. Quantity of Water in the River Clyde. — The breadth of the 

 Clyde, at the new bridge, Glasgow, is 410 feet, and its mean 

 depth 3| feet. The velocity of the watef at the surface is 1-23 

 inch, and the mean velocity of the whole water is 0-558,132 

 inch per second. From these data it may be inferred that the 

 quantity of water discharged per second is 76y cubic feet. This 

 amounts to 2,417,760,000 cubic feet, or 473,017,448 imperial 

 gallons, or 1,877,053 tons. The river Clyde drains about y^^th 

 of Scotland, or about ^^jd part of Great Britain. Hence, if the 

 water discharged into the sea by the Clyde afforded a fair ave- 

 rage of the whole island, the total amount of the water dischar- 

 ged annually by all the rivers in Great Britain would be only 

 155,795,399 tons, which does not amount to one-hundredth 

 part of the excess of the rain above the evaporation. — TJiomson 

 on Heat and Electricity, p. 268. 



CHEMISTRY. 



4. Freezing Point of Spirit of Wine. — The following state- 

 ment on this curious topic is given by Muncke and Gmelin : — • 



1. Good Coniac Brandy froze or sustained in Melville Island, 

 according to Captain Parry, a temperature of — 48°.5 cent. 



2. Alcohol of 801 sp. gr. at 20° cent., had its point of great- 

 est density, according to first experiments, at — 56°.6 cent., 

 consequently the conjectural freezing point was — 58° cent. 



3. Nearly pure alcohol of specific gravity 789, froze at — 79° 

 cent. 4. According to second experiments, alcohol of 791 

 sp. gr. attained its point of greatest density at — 89°.4 cent. 

 Therefore the conjectural freezing point was — 92° cent. — Pog- 

 gendorf^s Annalen, No. ix. 1829- 



5. Note on Robert Broion's Microscopical Observations on the 

 Particles of Bodies. — Muncke of Heidelberg finds the follow- 

 ing a simple and easy mode of shewing the motions of the par- 

 ticles. If we triturate a piece of gummi gutta?, the size of a 

 pin-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 microscope 



