Rurynotps—Recent Analyses of the Dublin Gas Supply. 305 
coal-gas, and supply a fair standard of composition by means of 
which any variations can be recognised :— 
Mean results of twelve Analyses made 
Constituents in 100 volumes. between November 25th, 1899, 
and February 16th, 1900. 
Carbon dioxide, . : é s 2°5 
Carbon monoxide, : : : 6-2 
Oxygen, . : é ‘ : 07 
Illuminating hydrocarbons, . : 4:3 
Non-illuminating hydrocarbons, . | 86:3 
| 100-0 
The results of a series of analyses of the Dublin supply 
performed since the 16th of February, 1900, are given in the table 
at end of this Paper (see p. 313). 
Apart from minor variations, to which I shall not further refer, 
the significant difference in this series is the increase in the per- 
centage of carbon monoxide found in the specimens examined. 
The first series of analyses proves that the ordinary coal-gas 
supply to Dublin during nearly three months contained on the 
average 6°2 per cent. of carbon monoxide. ‘The second series 
shows that there has been a gradual rise in the proportion of carbon 
monoxide until it had doubled on the 7th of March, and, two days 
later, the percentage had nearly trebled at 17:9: it then fellaway, 
and subsequently rose again to 13-9 per cent. on the 20th March, 
and reached 15-6 per cent. on the 24th of April.1 So great a change 
could, practically, only be due to the addition of water-gas. As 
soon as the trend of the results became clear, I communicated with 
the Gas Company (on March 6th), and they admitted that a pro- 
portion of carburetted water-gas had been mixed with the coal-gas. 
1 No analyses were made between March 21st and April 24th. 
Z2 
