diluted with air, in the person of a labourer, who was suddenly immersed
in it at the bottom of a well, and remained there three-quarters of an
hour. He was first affected with violent and irregular convulsions of
the whole body and perfect insensibility, afterwards with fits of spasm
like tetanus; and during the second day, when these symptoms had gone
off, he continued to be affected with dumbness.[2057]—It is worthy of
particular remark that, contrary to general belief, these effects may be
produced in situations where the air is not sufficiently impure to
extinguish lights. Thus M. Collard de Martigny relates the case of a
servant, who, on entering a cellar where grape-juice was fermenting,
became suddenly giddy, and, under a vague impression of terror, fled
from the place, dropping her candle on the floor and shutting the door
behind her. She fell down insensible outside the door, and those who
went to her assistance found on opening the door that the light
continued to burn.[2058]—Mr. Taylor indeed has since ascertained that a
candle will burn in air, which contains ten, or even twelve per cent. of
carbonic acid,[2059]—a proportion more than sufficient to cause
poisoning in no long time. It is also important to observe, that,
contrary to what would be expected from the statements of Sir H. Davy
and other experimentalists on the effects of the pure gas, it will often
happen that no odour or taste is perceived. M. Bonami, in an account of
an accident which happened at Nantes to two workmen who descended an old
well, says that the first while descending uttered a piercing cry and
fell down; and that as soon as his comrade, who tried to rescue him, was
lowered ten or twelve feet, he felt as if he was about to be suffocated
for want of breath, but perceived no strong or disagreeable smell.[2060]
It should be remembered therefore by workmen, that there may be danger
in descending pits where none is indicated by the sense of smell, or by
the extinguishing of a light.