In article ,
Jeff Layman wrote:

i like "Insect pests of glasshouse crops" by Miles & Miles (published
privately by H.C. Long in 1935). It amuses me greatly as it reflects an age
where 'elf&safety were noticeable by their absence. Here is a typical quote
on fumigating a greenhouse with hydrocyanic acid:

"The gas is highly poisonous to man, and the operator must leave the
greenhouse quickly once the fumigation is started, especially when the gas
is liberated rapidly as in the "pot" method."

FYI, the "pot" method involved getting a container with about 100ml of 33%
sulphuric acid in it, and dropping around 30g of sodium cyanide into it.
The amazing thing is that for large greenhouses several of these containers
would be used, so the operator would have to get to the next one pretty
sharpish after dropping the cyanide into the previous one!

That was also used to rid ships of rats. Because hudrogen cyanide
forms an explosive mixture with air, the ships' lighting had to be
off at the time ....


Regards,
Nick Maclaren.