Calcutta Asiatic Society, 71 



profound to he understood by merely hearing the paper read : but 

 they offer throughout new views of the doctrine of combustion 

 and flame, and practical apph cat ions of these views. 



On Thursday, Jan. 23, another paper was read by Sir H. Davy, 

 in which he describes some experiments for rendering invisible 

 combustions visible. By producing these combustions bv a heated 

 wire of platinum or palladium, the wire becomes ignited, and 

 continues so as long as the comlnistion can go on. A simple mode 

 of illustrating this new principle is by ger^tly heating a fine wire 

 of platinum having its extremity coiled three or four times, and 

 plunging it into a wine-glass containing a few drojjs of ether ; it 

 will become red hot, and continue red hot as long as any vapour of 

 ether mixed with air exists in the glass. It is a combustion in- 

 visible, except when it is produced by bodies that are tolerably 

 good conductors, but of small capacity and small radiating powers. 



He applies this new principle to a safety-lamp which will give 

 light in atinosjihcres containing so much coal gas as not to be 

 explosive. The twilled wire-gauze lamp gives a safe light in all 

 atmospheres that are explosive ; and by a little apparatus placed 

 in the top of it, it gives a beautiful light without flame in all 

 atmospheres, non-explosive from fire-dainp, that are respirable ; 

 and is relighted mtojiamehy explosive mixtures or atmospherical 

 air. 



Part of a short paper by Dr. Brewster was also read, detailing 

 some further experiments on the fffects of heat in changing the 

 powers of bodies in polarizing light. The Society then adjourned 

 till the Tth of Febrcary. 



CAIXUTTA ASIATIC SOCIKTY. 



At a late meeting of this Society several very interesting com- 

 munications were submitted to its consideration. Amongst 

 these was the journal of Mr. Eraser's Tour to the Sources cf 

 the Satlej and Jumna, and thence across a most difficult and in- 

 teresting country to the sources of the Ganges. A long and 

 curious document was also communicated respecting several 

 classes of robbers and murderers, known in the south of India 

 l)y the name of Phansesgars, and in the upper provinces by the 

 appellation of Thugs : tliey live in a regular society, and roam 

 the country in gangs under a regular Sirdar or chief. The com- 

 munication was sent by Dr. Sherwood, from Madras, and was il- 

 lustrated by several extracts from official reports made in this 

 part of India. An account of the sea-snakes that made their 

 appearance some time since in such numbers at Madras was al«o 

 forwarded by D.M'Kenzie: these snakes ])rove to be venomous 

 in a very high degree ; but the cstabli^ ment of medical aid near 

 the spot, and the ready application of '.he cau-de-luce, has prc- 

 E 4 vented 



