December 22, 192 1] 



NATURE 



523 



gas is water-gas"; and the Board finally recom- 

 mended that, subject to the foregoing principle, 

 the gas undertakings should be " free to deliver 

 to the consumer any mixture of the ordinary com- 

 bustible gases free from sulphuretted hydrogen 

 and not containing more than 12 per cent, of inert 

 constituents," whilst suggesting " the standard- 

 isation of burners in appliances for a limited 

 number of calorific values " between 400 and 

 500 B.Th.U. per cb.ft. The Board's main 

 recommendations, except as regards inert con- 

 stituents, were given effect to by the Gas Regula- 

 tion Act of 1920, which also provided {inter alia) 

 that the Board of Trade shall, as soon as may be 

 after the passing of this Act, cause an inquiry to 

 be held into the question whether it is necessary 

 or desirable to prescribe any limitations of the 

 proportion of carbon monoxide which may be 

 supplied in gas used for domestic purposes. 



Now, whilst it is generally admitted that there 

 are certain economic advantages to be gained by 

 supplying the public with coal-gas diluted with 

 water-gas, there are, nevertheless, weighty objec- 

 tions to an unlimited proportion of the latter being 

 allowed in a domestic gas supply, arising from the 

 poisonous nature of carbon monoxide (of which 

 water-gas contains about 42 per cent., as against, 

 say, 7 per cent, in coal-gas), and also from the 

 fact that the range of explosibility of- water-gas- 

 air mixtures is considerably wider than that of 

 coal-gas-air mixtures. Any large admixture of 

 water-gas with coal-gas in a domestic supply 

 would add materially to the dangers both of car- 

 bon monoxide poisoning and of gas explosions in 

 houses. 



The dangers of carbon monoxide poisoning with 

 gas containing a large proportion of water-gas 

 formed the subject of an official inquiry by a Com- 

 mittee (of which Dr. J. S. Haldane and the late 

 Sir William Ramsay were members) appointed by 

 the Home Office, whose Report (Cmd. 9164) was 

 issued in the year 1899. This Committee con- 

 sidered that the most probable manner in which 

 accidental death from gas poisoning would occur 

 would be from gas, inhaled during sleep, escaping 

 from a burner left full on unlighted; and, influ- 

 enced by experiments made by Dr. Haldane, as 

 well as by detailed information laid before them as 

 to the uses of water-gas in the United States and 

 its effect upon human health, and having in mind 

 also the nature of carbonic oxide poisoning and 

 the faulty character of gas pipes and fittings in 

 the poorer class of house, the Committee reported 

 that "the most direct, and in our opinion, the 

 NO. 2721, VOL. 108] 



only effective method of preventing danger from 

 water-gas is to fix a limit which the carbonic oxide 

 in a public and domestic gas supply shall not, in 

 ordinary circumstances, exceed." And, whilst 

 admitting the difficulty of assigning a limit ap- 

 plicable in all circumstances, they suggested that 

 12 per cent, of carbonic oxide would in ordinary 

 circumstances be a proper limit, with 20 per cent. 

 as the highest that should ever be allowed, and 

 that "only under special circumstances." Since 

 this Committee reported there has probably been 

 some (though not a great) improvement in the 

 character of the gas service-pipes and fittings in 

 the poorer class of houses. Also the more ex- 

 tended use of incandescent mantle lighting has 

 undoubtedly meant that less gas (in the ratio of, 

 say, 7 to 10) would nowadays escape into a bed- 

 room, from a burner left full on unlighted, than 

 twenty years ago. Therefore, if in 1899 some- 

 where between 12 and 16 per cent, of carbonic 

 oxide was considered to be, " in ordinary' circum- 

 stances," a proper limit, it would follow (the 

 poisonous nature of carbonic oxide remaining un- 

 changed) that to-day 20 per cent, might similarly 

 be considered a reasonable maximum limit. This 

 last-mentioned view was taken by the British Asso- 

 ciation Fuel Economy Committee in its Second 

 and Third Reports (1919 and 1920), and after- 

 wards supported, on physiological grounds, by 

 Dr. J. S. Haldane in his evidence before the 

 Board of Trade Committee. The adoption of such 

 a limit would mean that the gas undertakings 

 would be at liberty to supply a mixture of one 

 hundred parts of straight coal-gas with (up to) 

 fifty parts of blue water-gas, a fairly generous 

 allowance of the last-named. 



But the gas industry is to-day much more 

 strongly organised and entrenched than it was 

 twenty years ago. So, whilst admitting that 

 few undertakings would be inconvenienced by a 

 limit of 20 per cent, of carbonic oxide, except in 

 cases of emergency, and disclaiming any present 

 intention of supplying very high percentages of 

 water-gas (in London a proportion of only 33J 

 per cent, of carburetted water-gas being contem- 

 plated), its advocates argued before the Board of 

 Trade Committee that the advantages of cheaper 

 gas (although nowadays gas, at twelve to fifteen 

 pence per therm, seems a very dear fuel) out- 

 weigh the danger to human life feared from higher 

 proportions of carbon monoxide, and, therefore, 

 that no statutory limitation should be imposed. 

 Eventually, as the result of its inquiry, the Com- 

 mittee did so decide, being "greatly impressed by 



