of some of the Cornish Mines. 367 



thorns from winse or shaft; machine and water-fall forcing 

 air ; end of a core of two men ; no gunpowder used for some 

 time; specific gravity *997 



Oxygen. 

 Average of seven experiments with hydrogen, ni-\ ..„„ 



trous gas and quadrisulphuret of lime j 



Carb. acid. 

 Average of five experiments with lime water .... 0*07 

 Composition of sample : — 



Nitrogen 81*71 percent. 



Oxygen 18-22 



Carbonic acid . . . 0*07 



100-00 

 Sample of the above taken in a mercurial bottle gave the 

 following means : — 



Oxygen 18*34 per cent. 



Carbonic acid . . . 0*07 



Sample 17. Four gallons. 



Consols. — Copper mine, in slate. No other report forwarded 

 but that they were taken from the bottom levels. The pro- 

 per directions having been forwarded for the taking of the 

 samples, it is presumed the necessary precautions were adopted 

 as they came to hand in an inverted position, &c. &c. ; spe- 

 cific gravity *997. 



Oxygen. 



Average of four experiments with hydrogen 17*93 



Average of two experiments with nitrous gas .... 17*82 

 Average of three experiments with quadrisulphuret ~1 . ^ „_ 



of lime J 



Average of two experiments with phosphorus .... 17*60 

 Average of two experiments with platina ball .... 17*70 



Mean . . . 17*78 



Carb. acid. 



Average of three experiments with lime water .... 0*06 



Average of three experiments with potash 0*06 



Mean . . . 0*06 

 Composition of sample : — 



Nitrogen 82-16 per cent. 



Oxygen 17*78 



Carbonic acid . . . 0*06 



100*00 



