276 
MINUTES OE EEOCEEDINGS OE 
years afterwards to his sad untimely death, was engaged at one 
extremity of a low room (38 ft. long, about 30 ft. wide, and 10 ft. high) 
in converting one of the most important of these products—benzol— 
(which boils at 176° Fahr.) into nitrobenzol in a capacious retort, 
which suddenly cracked, and, yielding to the pressure of its contents, 
allowed the warm liquid hydro-carbon to flow over the operating table. 
There was a gas-flame burning at the other extremity of the laboratory 
and no other source of fire. Within a very few minutes after the 
fracture of the vessel a sheet of flame flashed from the gas-flame along 
the upper part of the room and communicated to the table upon which 
the liquid had been spilled. 
The firing of the ship “ Maria Lee 33 just now referred to was clearly 
proved to have been preceded by the explosion of a mixture of air and 
petroleum-vapour, produced by leakage or evaporation from the barrels 
stored in the hold of the vessel. The weather was very hot at the time, 
and, there having been a heavy thunderstorm the night before the fire, 
the hatches had been kept closed and covered over with tarpaulin, so 
that there was no possibility of ventilation. The vapour gradually 
diffused itself through the air in the ship during the night until the 
explosive mixture extended to the cabin at the after part. As the 
captain entered this cabin quite early in the morning (the immediate 
source of the fire was not clearly traced) a loud explosion occurred, and 
flame was immediately observed issuing from the fore part of the ship. 
A similar explosion of petroleum-vapour and air occurred not long 
since in a ship at Glasgow ; and, lastly, it was established by a sound 
chain of circumstantial evidence that the explosion of the powder-laden 
barge in the Regent's Park must have been caused by the ignition, in 
the cabin of the barge, of an explosive mixture of air and of the vapour 
of petroleum, derived from the leakage of certain packages of the spirit 
which were packed along with the powder. The description given by 
an eye-witness, on board a barge in front of the ill-fated “ Tilbury," of 
a bluish flash of flame, emanating from, the cabin of the barge within a 
very brief period of the explosion, corresponds with the result produced 
when flame is applied to a mixture of hydro-carbon vapour with a large 
proportion of air. The manner in which the freight of the barge was 
enclosed by tarpaulins precluded ventilation, and was most favourable to 
the gradual diffusion of inflammable vapour, from even slight leakages 
in the barrels, through the confined air, until an explosive mixture ex¬ 
tended to the opening in the bulk-head or partition, which in these 
barges^separates the cabin from the hold. 
It is impossible to protect heavy packages from rough usage, in the 
processes of unloading ships or other vehicles of conveyance; it is 
therefore most important that means should be adopted of thoroughly 
closing the vents of receptacles of petroleum spirit, by such means as 
are capable of sustaining ordinary rough usage without any injury to 
their efficiency, and that the improvement of the nature and construc¬ 
tion of the receptacles themselves'should be seriously considered, with 
the view of reducing the liability to accidents resulting from the escape 
of the spirit or its vapours, and the consequent creation of danger 
connected with the transport and storage of these valuable illuminating 
materials. 
