414 



5. In mines where the Davy lamp is obliged to be used, 

 it is necessary that the lamp should be cleaned, the gauze 

 of every lamp examined, and locked before being delivered 

 to the men each day, by a competent person. It is usual 

 for the colliers to clean them themselves, but one defective 

 lamp may be sufficient to explode the whole mine ; and at 

 any rate they should be inspected before being permitted 

 to descend. This lamp, I believe, when clean, so that no 

 coal dust will adhere to it, is perfectly safe in carburetted 

 hydrogen, but in a mixture of sulphuretted hydrogen, some- 

 times evolved when pyrites is exposed to the action of .water, 

 the Davy lamp is not to be relied upon. 



6. One word respecting the resuscitation of those who 

 are rescued from an exploded pit. All sorts of barbarous 

 remedies are adopted; even Mr. Buddie says before the 

 Committee of the House of Commons, that to dig a hole 

 in the ground, and place the suiFerer's head in it, covered 

 up by earth, is the best plan in use. The mode of death 

 is as follows ; — 



1. Carbonic acid enters the lungs. 



2. The blood passing through the lungs, does not give 



out carbonic acid and receive oxygen, which is 

 necessary to life. 



3. Dark blood, not purified by air, is transmitted to the 



left side of the heart, and thence to the brain and 

 other organs. 



4. The heart continues to act, circulating dark coloured 



blood, but its actions become gradually weaker, 

 and in the course of a few minutes cease altogether. 

 The heart is the ultimum moriens, and ceases to 

 act from impairment of nervous energy — the result 

 of black blood poisoning the brain. 



