Subscribe now

Letter: Sir, it's snowing

Published 24 July 2004

From Chris Rundle

Ian Clark’s mention of metaldehyde evokes memories of the golden age of British ironmongery, when the local store would happily sell not merely all the ingredients necessary for the preparation of explosives in the comfort of one’s garden shed, but all kinds of other exciting (and now banned) substances (The Last Word, 10 July).

The metaldehyde bar was, in fact, dual-purpose, functioning as both firelighter and rat poison. It also had a third and little-known property: applied to hot metal, such as a heated poker, it would give off immense quantities of what looked like snowflakes which, being considerably lighter than the real thing, would float around in air currents for many minutes before finally settling.

The most spectacular demonstration I can recall was when, with judicious timing and the super-heating of the coke-fired stove which served the sixth-form block, we managed to create a magnificent and near-impenetrable indoor blizzard in time for the last history lesson before Christmas – though God knows what we inhaled in the process.

The editor writes:

• While metaldehyde clearly has a number of entertaining uses, it is also the active ingredient of slug pellets and is a very toxic chemical. It should only be used in controlled environments and certainly not while there is any danger that children will be exposed to it.

Williton, Somerset, UK

Issue no. 2457 published 24 July 2004

Sign up to our weekly newsletter

Receive a weekly dose of discovery in your inbox. We'll also keep you up to date with New Scientist events and special offers.

Sign up
Piano Exit Overlay Banner Mobile Piano Exit Overlay Banner Desktop