Radioactive sources

[George A. Gleason]

Radioactive sources: if you're interested in thorium, it can be found in
Coleman lantern mantles: the little cloth bags you tie over the apertures in
the lantern where the flame appears.  These are apparently saturated with
the stuff.  I got the word from an engineer at a nuclear plant some years
ago, and was able to verify it at least partially: a geiger counter held
next to Coleman lantern mantles at the store got a very clear reading in the
range of 20mR/hr.  The counter I was using was not sensitive to alphas, so I
presume it was getting betas.  The thorium in the lantern mantles could
presumably be extracted with hydrochloric acid or by some other means.
Clearly not for the amateur, but something which could be done in a lab with
appropriate precautions.  
-gg