MIXED GASES, 411 



water, or through successive layers of hydrate of lime, to remove 

 carbonic acid, sulphuretted hydrogen, &c. ; it is finally received in a 

 gazometer, (see p. 214,) thence distributed by tubes, and burned at 

 proper orifices furnished with stop cocks. 



(h.) It is now evident, that the illuminating power of gases is de- 

 pendent not only upon the quantity of olefiant gas in them but upon 

 the other compounds containing still more carbon, as the quadro- 

 carburet, the vapor of naphtha, &c. 



(*.) Mr. Daniel employs resin,* dissolved in oil of turpentine ; it 

 falls, drop by drop, into the retort, and the volatile oil, by passing 

 over in vapor, is recovered. This gas is employed by Mr. Gordon 

 in his portable lamps, and is said to be equal to oil gas. 



PORTABLE GAS LIGHT. 



"One of the greatest obstacles to the 

 general employment of gas lights, as a sub- 

 stitute for candles and lamps, is the neces- 

 sity of pipes leading from gazometers, to 

 all situations where the light is wanted. The 

 condensation of the gas in strong metallic 

 receivers, has been resorted to in order to 

 obviate this difficulty. This process may 

 be illustrated by means of the apparatus 

 described for the impregnation of water 

 with carbonic acid. 



"It is only necessary to exchange the 

 communication with the reservoir of car- 

 bonic acid gas, for a similar communication 

 with a reservoir of olefiant gas, and the cop- 

 per vessel being first exhausted of air, to 

 condense the gas into it. The syphon used 

 to draw off the carbonated water, is repla- 

 ced by a tube and cock, terminating in a 

 capillary perforation. Through this, the 

 gas may be allowed to escape in a proper 

 quantity to produce a gas light when inflamed." Dr. Hare. 



SAFETY LAMP OF SIR H. DAVY. 



1. REMARKS. 



(a.) It has long been notorious that a deadly gas infests the mines 

 of bituminous coal, called by the miners, the fire damp or wild fire, 



* Dr. Hare, several years ago, employed common rosin, in New York, and it is 

 now used there to afford gas light; he. obtained also a substance, rising in distilla- 

 tion, which not a little resembled naphthaline. 



