467 



these cases, between the single or double portion of sulphur, which 

 of them is to be regarded as the elementary atom, according to Mr. 

 Dalton's view of the subject. 



Professor Berzelius next examines various compounds, which may 

 be termed carbo-sulphurets of the alkalies and earths. The carbo- 

 sulphuret of ammonia sublimes unchanged in close vessels ; but when 

 exposed to air, the carbon is deposited, and hydro-sulphuret is pro- 

 duced ; and, in the same manner, the carbo-sulphurets of lime, ba- 

 rytes, and strontia are decomposed when moisture is present, and 

 hydro-sulphurets of these earths are formed. 



The remainder of this appendix contains the analysis of a solid 

 white crystalline compound, having the appearance and volatility of 

 camphor, formed by exposure of the sulphuret of carbon during three 

 weeks to the fumes of strong nitro-muriatic acid. It is insoluble in 

 water, but dissolves in alcohol, ether, and in oils, whether fixed or 

 volatile. When this compound was sublimed through a red-hot tube 

 containing iron wire, it was decomposed, and found to consist of mu- 

 riatic acid, 48'74 ; sulphurous acid, 29'63; and carbonic acid, 21*63. 



On the Means of procuring a steady Light in Coal Mines without the 

 danger of Explosion. By William Reid Clanny, M.D. of Sunder- 

 land. Communicated by William Allen, Esq. F.R.S. Read May 20, 

 1813. [Phil. Trans. 1813,;?. 200.] 



The author having resided several years near the coal mines in the 

 county of Durham, has paid much attention to the circumstances of 

 those explosions which so frequently occasion the death of many in- 

 dustrious people, and has contrived a lamp, which he thinks likely 

 to answer the purpose of illumination, without any danger attending 

 its use. 



He is of opinion, that ventilation, as at present practised, has little 

 or no effect in preventing explosions ; since it has no tendency to di- 

 minish the quantity of inflammable gas emitted by the old workings, 

 which must always be in danger of exploding wherever it comes into 

 contact with atmospheric air, if light be applied to it. The partitions 

 and folding doors put up at the entrances of old workings appear to 

 be very inadequate to prevent the occurrence of such explosive mix- 

 tures ; and their frequency is shown by the number of accidents 

 which the author enumerates as having taken place in his own neigh- 

 bourhood alone in the course of the last seven years. The number 

 of explosions in the course of that time has been six ; and these have 

 destroyed more than two hundred pit-men, who have left wives and 

 children in a state of poverty and distress. In some instances, large 

 pumps have been erected at the top of the shaft, worked by steam- 

 engines, for the purpose of drawing off the inflammable gas from 

 those parts where it most abounds ; but even these have been found 

 insufficient, since the engine will not, in all instances, be applied to 

 the part where it is most wanted : and it is estimated, that wherever 

 2 H 2 



