394 Intelligence and Miscellaneous Articles. 



Yellow Mica. 



SUica 49-78 



Alumina 19'88 



Peroxide of iron 13-22 



Potash 8-79 



Lithia 4-15 



Fluorine 4-24—100-06. 



Annates de Chimie et de Physique, pp. 69-72. 



METEORIC IRON FROM POTOSI. 

 H. M. Juben, a Lieutenant in the French Navy, among other mi- 

 nerals which had been presented to him, brought from Peru a piece 

 of meteoric iron found near Potosi in Bolivia ; it was stated to him 

 to be meteoric iron of great purity ; it is cavernous, filled with 

 vacuities, most of which are irregular, but some have the form of a 

 rhombic dodecahedron ; some of them also are filled with a green- 

 ish vitreous substance similar to the olivine of Pallas. No traces 

 whatever of fusion appear, although the mineral evidently indicates 

 the action of a high temperature. The tenacity of this iron is ex- 

 tremely great, but it is readily hammered and filed. It does not 

 oxidize even when exposed to a moist atmosphere. Its sp. gr. is 

 7-736. The mean of three analyses performed by M. Morren give 

 us its composition 



Iron 90-241 



Nickel 9-759 



100- 



This iron is remarkable on account of the large quantity of nickel ; 

 no trace either of copper, cobalt, or manganese was discoverable. 

 The specimen is deposited in the Museum of Angers. — Chronique 

 Scientifique, 24 Feb., 1839. 



PHOSPHORESCENT POWER OF ELECTRICAL LIGHT. 



M. Becquerel has read a memoir to the Institute on some new 

 properties which electrical light possesses of acting as a phosphores- 

 cent power. After a brief history of what had been previously done 

 with respect to johosphorescence, M. Becquerel proceeds as follows : 



I shall begin with first showing that electrical light is capable of 

 producing phosphorescence, not as a consequence of a shock or by 

 electrical influence, as was formerly supposed, but on account of pro- 

 perties peculiar to its radiation. For this purpose some freshly cal- 

 cined oyster-shells are placed in aporcelain capsule, and ata distance of 

 about -^ of an inch, a discharge from eighteen jars is passed through 

 them. The shells soon became luminous, and the light disappears 

 more or less readily according to their degree of excitabilit)'. 



On successively placing the shells at a distance of about 4 , 20, 80, 

 130, &c. inches, the phosjAorescence always appeared ; theeff'ect di- 

 minishing in proportion to the distance. It is even apparent at a 

 much greater distance still, and where usual electrical influences are 

 not distinguishable. I will also add that green fluors exhibit the 



