PROFESSOR H. B. DIXON ON THE RATE OF EXPLOSION IN GASES. 
145 
from all liquids but water, and, in the “ dry ” experiments, oil of vitriol saturated 
with clilorine. The drying apparatus consisted of a “ Winkler ” worm, a series 
of bulbs, and a large U-tube packed with pumice, all filled with boiled oil of vitriol. 
The following table gives the mean of each pair of experiments with the dry and 
with the moist gases saturated at 14°. 
Table XXXVI. — Rate of Explosion of Hydrogen and Chlorine, 
Dry. 
Moist. 
1748 
1724 
1745 
1707 
1737 
1730 
1748 
1750 
Mean 1745 
Moan 1720 
It appeared, therefore, that the explosion, once started, travelled at a slightly 
faster rate in the dry than in the wet gases, the steam appearing to act merely 
as a diluent. 
These experiments, together with the analysis of the mixture which issued .from 
the end of the explosion tube, showed that it was possible to fill a long tube directly 
from the electrolytic cell with hydrogen and chlorine in equal volumes, and that the 
mixture detonated in a glass tube of 10 mm, diameter. To prove the constancy of 
the rate of explosion, and at the same time to have a longer interval of time to 
measure, it was necessary to obtain a longer explosion tube. The difficulty of joining 
up long pieces of unannealed glass-tubing led me to try the glass-lined wrought-iron 
tubing manufactured by Messrs, Hylands, at Barnsley. Having found that this 
tubing answered the purpose, I made an explosion tube 40 yards long, and ^-inch 
diameter, by joining together a number of six-feet lengths. The junctions were 
made by fitting an asbestos waslier on to the ends of each tube, and screwing them 
together with a nut. The tube was supported at intervals by wooden brackets 
fastened to the wall of a long corridor. The explosion tube so put together was 
perfectly gas-tight ; it was unaffected by the chlorine passed into it during the 
experiments, and it stood the shock of many explosions without leaking. This tube 
was filled, as before, direct from the electrolytic cell of aqueous hydrochloric acid. 
The cell and drying vessels were all of glass with ground glass joints. Two short 
tubes charged with hydrogen and oxygen were used, as before, to carry the silver 
bridges. They were joined to the long tube immediately before the explosion. The 
mean rate of explosion of dry hydrogen and chlorine in this tube was found to be 
1723 metres per second—as the result of three pairs of exjieriments :— 
MDCCCXCIII.—A. u 
