RESPIRATION 321 



main intake of a mine. If the breathing has stopped artificial res- 

 piration should be applied promptly; and this can best be done by 

 Schafer's well-known method. If oxygen is available it should be 

 given at once. It immediately increases greatly. the amount of dis- 

 solved oxygen in the blood, and also expels far more rapidly the 

 CO from the blood, as will be evident considering the properties 

 of CO haemoglobin. The oxygen will do most good at first, and 

 may be continued with advantage for at least twenty minutes. Suit- 

 able apparatus for giving oxygen can now be obtained easily. Hen- 

 derson and Haggard have recently shown, however, that owing to 

 the great washing out of CO2 which occurs during the hyperpnoea 

 produced in acute CO poisoning, or perhaps owing to temporary 

 exhaustion of the respiratory center, the breathing is apt to re- 

 main for some time inadequate. ^^^ They found by experiments on 

 animals that under this condition the removal of CO from the 

 blood is greatly accelerated by adding CO2 to the air or oxygen 

 inhaled. The desirability of having some safe and practicable 

 means of adding CO2 to oxygen used in reviving men poisoned by 

 iCO seems evident from these experiments. 



A man who has been badly gassed by CO, and has been un- 

 conscious for some time, is sure to have very formidable symptoms, 

 lasting long after all traces of CO have disappeared from the 

 iblood. He may never recover consciousness at all; but when he 

 does his nervous system generally is likely to remain very seriously 

 affected for days, weeks, or months, so that he requires to be care- 

 fully watched, nursed, and treated. Mental powers and memory 

 may be much impaired, and the nervous system seems to be in- 

 jured in many different directions. Thus the regulation of body 

 temperature is apt to be imperfect, and symptoms resembling those 

 of peripheral neuritis are common. A condition of neurasthenia, 

 similar to that so often seen during the war, appears to result fre- 

 quently, with the usual affections of the respiratory and cardiac 

 nervous system. In some cases there seems to be acute dilatation of 

 the heart ; and probably almost every organ in the body has suf- 

 fered from the effects of want of oxygen. 



As mines grow deeper and warmer, the importance of the wet- 

 bulb temperature in connection with mine ventilation becomes 

 more and more prominent. The reasons for this will be evident 

 from what has already been said on this subject; especially when 

 the fact that a miner has to do hard physical work is also taken into 



"* Yandell Henderson and Haggard, Journ. of Pharmac. and Exper. Therap., 

 XVI, p. 1 1, 1920. 



