PROFESSOR H. B. DIXON ON THE RATE OF EXPLOSION IN GASES. 
Ill 
dry mixture, until a maximum velocity was attained when between 5 and 6 per cent, 
of steam was present. 
The experiments were conducted in the following way :—In the “dry” experiments 
the coil of pipe was heated and a current of dry air drawn through it. The mixture 
of carbonic oxide and oxygen was passed into the dry coil through drying apparatus, 
consisting of two wash-bottles and three pumice towers contaiiiing boiled oil of vitriol, 
and then two long tubes packed with anhydrous phosphoric acid. The mixture under 
these conditions is called “well-dried”; it readily transmits the explosion. In the 
next experiments the phosphoric acid tubes were omitted; the mixture is called 
“dried.” For saturating the gases with steam the mixture was led through water 
in three small wash-bottles before entering the coil. The first wash-bottle was kept 
about 5° C., the second about 3° C., and the third exactly 1° above the temperature 
at wdrich the mixture was to be exploded. The last bottle and the connections 
between it and the coil were kept entirely surrounded by water. The gas, on its 
passage through the wash-bottles, carried over steam, which was partly condensed in 
the cooler wash-bottles and in the coil. While the gas was being admitted to the coil 
the water jacket was kept about ’5° above the final temperature required. When the 
tube was full the source of heat was removed, and the water in the jacket well 
stirred. When the exact temperature was reached the stop-cocks were closed and 
the gases fired. This arrangement ensured that the gases wmre saturated with 
moisture, and prevented any accumulation of liquid in the coil which might have 
retarded the explosion. 
In the following table the mean results obtained with the dried and with the 
moistened gases are given :— 
Table XI.—Kate of Explosion of Carbonic Oxide and Oxygen saturated with Steam 
at Different Temperatures. 
Condition. 
Per cent, of 
steam present. 
Mean rate in 
metres per second. 
Well dried. 
1264 
Dried. 
1305 
Satru’ated at 10° C. 
1-2 
1676 
„ 20° C. 
2-3 
1703 
„ 28° C. 
3-7 
1713 
„ 35° C. 
5-6 
1738 
„ 45° C. 
9'5 
1693 
„ 55° C. 
15-6 
1666 
„ 65° C. 
24-9 
1526 
» 75° C. 
1 
38-4 
1266 
The maximum rate was obtained when the mixture was saturated at 35° C.— i.e., 
contained 5’6 per cent, of steam. Excess of steam slowly retards the rate. A few 
