Scientific Intelligence.— Natural History. - 167 



ether and alcohol. It is observed also that a mechanical pressure 

 upon the water produces the same effect, and that this phosphores- 

 cence is rarely perceived in calm water. — Bib. Univ. Juin, 1828. 



6. Analysis of a new mineral, from Hoboken, by M. Wachmeister. 

 (An. de Pog. 1828, p. 521.) — There has been found in the serpen- 

 tine of Hoboken, state of New York, [New Jersey,] in the United 

 States, with the carbonate of magnesia, a white powder, which has 

 been taken for hydrate of magnesia. This mineral is composed of 



Magnesia, - - - - .4241 



Carbonic acid, - - _ .- .3682 



Water, ----- .1853 



Silica, oxide of iron, he. - _ - .0223 



Its formula is Mq Aq » + 3MqC ^ . — Jour, des Mines, T.V. p. 309. 



7. Temperature of the atmosphere and of plants, &fc. — Dr. J. 

 Guerin, of Avignon, in France, has ascertained, by a great number 

 of observations, made at various seasons on Mount Ventoux, a conical 

 and isolated mountain, whose summit is one thousand toises above 

 the sea, that in the latitude of 44° and at an elevation of one thou- 

 sand toises, the temperature of the atmosphere decreases one degree 

 (centigrade) in summer for every eighty toises in elevation, and one 

 degree in winter for every one hundred toises, and in the interme- 

 diate seasons one degree in ninety toises. 



As a proof of the cold produced in solid substances by radiation, in 

 a clear atmosphere, Dr. Guerin has ascertained by nice observation, 

 that the temperature of trees and plants is very often much inferior 

 to that of the air. On the 24th of January, 1827, at 7 A.M. the 

 air being — 11.3 (C.) the snow adhering to the branches of a cypress 

 and other plants and shrubs, was — 14.5 and 15, that is to say, 3.5 

 lower than the air. On the 1st of April, 1828, the trees and flowers 

 were —2.5 and the air +1-^ (G.) 



The mean temperature of Avignon, obtained by twenty seven years, 

 observation, is 14.38 (C) = 57.88 Far. The height of the baro- 

 meter, from a mean of twenty years is seven hundred and sixty two 

 millimetres. The annual quantity of rain, from a mean of twenty 

 years, is 20 in. French, 3.8 litres. 



The friends of meteorology must wish to. obtain, from the different 

 countries of the globe, data as complete as those furnished by Dr. 

 Guerin relative to the country which he inhabits. — Bib. Univ. Juil- 

 let, 1829. 



