236 Scientific Intelligence. 



himself round several times, and literally twisted off his leg at the 

 third joint, leaving the limb in the wood. He then moved into the 

 hive, as if nothing had happened. This is the only instance, I have 

 seen, or have ever read, or heard of, of the spontaneous self muti- 

 lation of an insect, but as I am no naturalist, the fact may be well 

 known. At any rate, if you think it worth any thing, you can make 

 what use of it you please, and I pledge myself as to its accuracy." 



III. — Calcarco Sulphate of Barytes. 



This mineral was discovered among the debris of the abandoned lead 

 mine of Nuissiere near Beaujeu, by the Marquis de Dree, and hence, 

 has been called, Dreelite, {Ann. des Mines, viii. 237.) It consists 

 of white, pearl)', rhomboidal ciystals without any modifications.. It 

 possesses a triple cleavage parallel to the faces of a rhombohedron. 

 Its primitive form appears to be an obtuse rhombohedron, the dihe- 

 dral angle of which may be about 93" or 94°. It, therefore, resembles 

 chabasite. Its specific gravity is between 3-2 and 3-4 and its hard- 

 ness a little above that of carbonate of lime. Before the blow-pipe 

 fuses into a white glass which is coloured blue by nitrate of potash. 

 It occurs in small crystals disseminated over the surface of a quartz 

 rock. Dufrenoy found its composition 



Sulphate of barytes, . . 61-731 



Lime, 11-980 



Silica, 9-712 



Sulphuric acid, .... 8-346 



Alumina, 2-404 



Water, 2-308 



Loss and Carbonic acid, . 3-519 



100-000 

 This is equivalent to 2 Br Sl-f Cal SI; and hence may be considered 

 as a purer form of the amorphous Calcareo-sulphate of barytes de- 

 scribed by Dr. T. Thomson in this Journal, vol. i. 370. 



IV. — On the influence of the Moon on the Barometer. 



The Rev. Mr. Everest, of Bengal, has shewn, that on an average of 

 10 rainy seasons, in India, the daily amount of the rain-fall diminished 

 as the declination of the moon increased, until it reached between 10° 

 and 15°; but after that distance, the reverse took place, and the 

 amount of rain-fall increased as the declination increased. The 

 general average of 10 years for every 5 D distance from the equator, 

 gave the following curve : 



0^ 5 U 10 ' 15° 20- 1 25° ) 

 •321 -271 -256 -259 -347 \ from the Equator. 

 He has also found that the greatest depressions of the barometer 

 do not (as some have conjectured) coincide with the days of conjunc- 

 tion and opposition of the moon, neither with the days of her perigee ; 

 but that they coincide, or nearly so, with the days of her maximum 

 monthly declination. — Bengal Asiatic Sue Journal, May, 1835. 



