46 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



second, general exhaustion of the nerve centres; third, lower- 

 ing of the body temperature. Under these conditions the 

 popular remedies for all cases of insensibility, viz.. treating 

 externally with cold water and internally with whisky, is 

 radically wrong. The lowering of the temperature of the 

 body is not only due to shock, but also to the fact that CO and 

 CO 2 directly affect the oxygenatioii of the blood, so 1 " every 

 effort should be taken to raise the temperature of the body. 

 As alcohol has been proved to increase shock, its use should 

 also be avoided. In every case of gassing, where the act of 

 Swallowing is voluntarily possible, an emetic should be at 

 once administered. The advantage of emptying the stomach, 

 and of emptying the lungs of mucus and of any unahsorbed 

 gas in their ultimate recesses, which the act of vomiting does 

 more effectively than any voluntary effort, more than counter- 

 balance any momentary depressing effect of the emetic. In 

 every case of gassing, which is so profound as to cause deep 

 coma and arrest the breathing, artificial respiration must be 

 started immediately and persevered in so long as there are any 

 indications of life- 

 Methane, light carburetted hydrogen, marsh gas or fire 

 damp. Strictly speaking, fire damp is a mixture of gases, the 

 largest proportion beinp CH^, with which is associated other 

 hydrocarbons, such as olefiant gas (CfjHi), hydrogen, carbon 

 dioxide, oxygen, and nitrogen. This gas is held in the pores 

 of the coal in more or less high tension, from which it issues 

 with a hissing noise. Blowers are more or less steady dis- 

 charges of gas from coal for a long time ; in some places the 

 pressure from blowers has been measured and found to be as 

 high as 9001bs. per square inch. In such cases of high pres- 

 sure a fall in the barometer can have but little influence, for 

 supposing the fall was equal to one inch of the water gauge, 

 which would be exceptional, this only means 5.21b. per square 

 foot or ll-288ths of a pound on the square inch, so the effect 

 on the gas issuing from the coal can only be very trifling. 

 Atmospheric changes, however, affect fire damp in goaves. 

 V\c occasionally hear of cases where death has occurred in 

 houses, due to an escape of gas. Methane is not an inherent 

 poison; it is simply a non-supporter of life, causing suffoca- 

 tion ; but illuminating gas contains in admixture about 5 per 

 cent, of carbon mon-oxide, which is decidedly poisonous. In 

 coal mines the men are w r arned of the presence of small quan- 

 tities of gas by the blue halo round the flame of their lamps. 

 Fire damp is ignited by a flame as both its constituent elements, 

 carbon and hydrogen, unite with oxygen: 7 to cS per cent, in 

 air free from dust becomes explosive, with 10 to 12 per cent, 

 the explosion attains its maximum, with 20 per cent, the mix- 

 ture no longer explodes, but extinguishes a flame plunged 



