218 Scientific Proceedings, Royal Dublin Society. 



kindly carried out by the same authority a,t my request this week, 

 was 16*2 per cent, of carbon monoxide. From the health point of 

 view, carbon monoxide is the most objectionable of all con- 

 stituents of coal-gas. Its presence in increased quantity is to 

 be ascribed to the addition of what is known as " carburetted 

 water-gas" to the coal-gas during the process of manufacture. 

 Carburetted water-gas is made by passing steam over red-hot 

 coke, whereupon the carbon of the coke combines with the oxygen 

 of the water- vapour, and forms carbon monoxide, whilst hydrogen 

 is liberated, according to the equation H 2 + C = CO + H 2 . The 

 mixture of carbon monoxide and hydrogen burns with an almost 

 non-lumiDOus flame, and is nearly inodorous. A subsequent 

 addition of vapourised petroleum or other oils confers upon it 

 illuminating power, and a powerful odour, which is, to most 

 people, very objectionable, 1 but which has the important advantage 

 of betraying its presence. Manufactured as it is to a large extent 

 from the by-products of the ordinary industry, carburetted water- 

 gas is cheap ; and its addition in considerable volume to the 

 ordinary gas is therefore profitable to the producing company. 

 It contains about 30 per cent, of carbon monoxide, and its 

 introduction into dwellings is therefore by no means a matter 

 of indifference to the public. Carbon monoxide is an extremely 

 dangerous substance, which owes its deleterious effect on the 

 animal economy to the intense affinity which it has for the 

 haemoglobin of the blood— an affinity which has been calculated 

 to be almost exactly 300 times as great as that between haemo- 

 globin and oxygen. For it has been found 1 that if blood be 

 shaken up with a sample of air containing 0*07 per cent, of CO — 

 in other words, 10,000 volumes of which contain 2,100 volumes of 

 oxygen and 7 of CO — one-half of the haemoglobin will be found 

 saturated with O, and the other half with CO, which amounts to 

 saying that air containing only one-three-hundredth of its volume 

 of carbon monoxide will half saturate the blood with that gas. 

 The result is that at each inspiration of such air a certain pro- 

 portion of the haemoglobin is deprived of its oxygen- carrying 

 function, and after a longer or shorter time, according to the 

 proportion of CO present, the amount of functional haemoglobin 



1 See Lorrain Smith : British Medical Journal, April 1st, 1899. 



