[202 J 
XXI. 
RECENT ANALYSES OF THE DUBLIN GAS SUPPLY 
AND OBSERVATIONS THEREON. By J. EMERSON 
REYNOLDS, M.D., So.D., F.R.S., Professor of Chemistry, 
Trinity College. 
[Read Aprin 25; Received for Publication Aprit 27; 
Published May 12, 1900.] 
LarcE quantities of the city gas are used for various purposes in 
Trinity College, and it is the practice to analyse it occasionally in 
the Chemical Laboratory in order to ascertain whether its quality 
is maintained. In the course of the series of analyses made during 
the last five months, in conjunction with my excellent Assistant 
Mr. E. A. Werner, F.1.C., I detected a marked change in com- 
position which began in February and continues to the present 
time. This change indicated that plain coal-gas was no longer 
supplied, but that a mixture which includes a considerable propor- 
tion of ‘‘water-gas”’ has since been delivered. On the 12th of 
last March I drew attention to this change in the course of a 
lecture delivered in College on that date. Extracts from that 
lecture appeared in the daily papers and led to considerable 
discussion, in the course of which opinions were attributed to me 
as to the probable effects of the change which I did not express 
and cannot be in any way responsible for. 
I therefore desire in this paper to place on record the analyses 
made, and to shortly state the related considerations which should 
influence opinion as to possible danger attending the public use of 
mixtures of coal and water-gas. 
Twelve analyses of the Dublin gas supply performed between 
the 25th of November, 1899, and the 16th of February, 1900, 
gave the following mean results, which agree with those of average 
