158 Ml Calder mi the Geology of India. 



imperfectly formed gauts, disseminated tliroughout with veins 

 of steatite. Here, too, traces of coal have recently been dis- 

 covered, which is hkely to be productive ; and gold is frequently 

 found in the sands of the Mahanuddee, probably from the val- 

 ley of Sumbulpore. We next trace the laterite, increasing in 

 extent all the way to Midnapore, and thence continuing north- 

 wards by Bissunpore and Bancorah to Beerboom. 



We must pause here, and take another opportunity to re- 

 sume Mr Calder's comprehensive essay on the geology of 

 India. 



On some New Bodies which strongly absorb Light. By 



M. OSANN. 



1 HE phosphorescent bodies prepared by M. Osann, are the 

 following : — 1. Phosphorus of Antimony. To obtain it, cal- 

 cined oyster-shells are taken, of which the whitest and most 

 porous are selected. After freeing them of all impurities, 

 they are put into a crucible in the following manner: — The 

 bottom of the vessel is covered with a finely pulverized sulphu- 

 ret of antimony ; there is then placed a shell, which is covered 

 with a new layer of the same powder, then a second shell, and 

 so on, until the crucible is filled. To distribute the powder 

 equally, a small sieve should be used. Each layer must be 

 about two lines in thickness. The crucible is then closed, and 

 exposed for an hour to a red heat. The upper shells, and 

 those at the bottom, which are commonly spotted, must be re- 

 jected. When the phosphorus thus obtained is exposed to the 

 solar light, and then taken to a dark place, it shines with a green- 

 ish-white light, and is superior to Bologna phosphorus, both in 

 the intensity and in the duration of its light. This greenish 

 glow, of a pistachio colour, which is characteristic, is the same in 

 all points of the phosphorescent body. By a red heat, conti- 

 nued for a long time, it is lost, and is then replaced by a white 



2. Phosphorus of Realgar. — This is prepared in a similar 

 manner, the calcined shells being treated with red sulphuret of 

 arsenic. It produces a blue light, resembhng the flame of sul- 

 phur. As in the preceding phosphorus, the perfectly white 



