252 ON EXPLOSIONS IN CHEMICAL LABORATORIES. 
cipitate into a small glass-bottle, and was closing it with a 
glass-stopper, when the bottle was blown to atoms in his 
hand. This explosion may be explained by the circumstance 
that close to the purple precipitate several other preparations 
had been dried and preserved, by which probably ammo- 
niacal gas had been developed, so that gradually fulminat- 
ing gold was formed. 
The second explosion was caused by detonating silver, 
of which about two drachms had been prepared, and after 
drying taken from the filter and placed on a sheet of glazed 
paper, with the intention of introducing it from the latter 
into a bottle ; it had been removed with the greatest care 
from the filter, so that nothing could adhere to the paper. 
In order to see whether the filter would detonate, Mr. 
TrommsdorfF threw it into a wind-furnace, which contained 
red-hot coals, and stood about four or five paces from the 
table on which the detonating silver was lying. Unfortu- 
nately the detonation in the furnace was so violent, and 
caused so strong a vibration of the air, that the silver on the 
table simultaneously exploded, and caused considerable 
damage. The experimenters remained for some time quite 
deaf, and the explosion caused great alarm throughout the 
whole town. 
The fatal accident which happened in 1S42, at Apothe- 
caries Hall, London, and by which the much lamented 
operator, Mr. Hennel, lost his life, must be yet fresh in the 
memory of our readers. 
On another occasion, some melted copper was poured 
into a crucible, when immediately the fused metal was 
thrown up with great violence over the heads of the 
bystanders to the ceiling. The operator had cleansed the 
crucible, but not sufficiently wiped it, so that probably a 
few drops of water might have remained at the bottom, 
and these were converted into steam as soon as the glowing 
metal came in contact with them. 
The fourth and more violent explosion occurred during 
