From: chideste@pt.Cyanamid.COM (Dale Chidester)
Newsgroups: sci.chem
Subject: Re: Indoor fireworks
Date: 12 Mar 1997 21:19:36 GMT

John,

I think you're confused with the volcano demonstration.  Ammonium
dichromate decomposes themally to give a large volume of chrome(III)
oxide, which is the green "ash" from the "volcano".

Snakes, or "Pharaoh's Serpents" are dried pellets of mercuric thiocyanate
Hg(CNS)2.  They can be ignited with a match or put on a very hot surface. The
reaction leavs a porous black residue composed of foamed carbon mixed with HgS.
Significant Hg vapor is formed, so these should only be used in well ventilated
areas.

Prepare by mixing Hg(NO3)2 in water with aqueous KCNS.  Wash white ppt.
with cold water, press dry between filter paper or allow to air dry out
of the light before pressing into pellets.  Excessive pressure is not
required.  They are very poisonous, so be sure to use all precautions.

The above is for information only and not a recommendation from me!

		Dale

From: dwilkins@mega-com.com (Don Wilkins)
Newsgroups: sci.chem
Subject: Re: Indoor fireworks
Date: Fri, 14 Mar 1997 23:02:24 GMT

On 13 Mar 1997 01:22:11 GMT, "Tom Miller" <tmiller@raisiochem.bc.ca>
wrote:

>Nope.  Nitrated naphtha pitch.
>
>Mercury fulminate (mercuric thiocyanate) is the primary component of
>primers (percussion explosible detonators in the friendly end of bullets). 
>Not a candidate for countertop chemistry. 

I would agree that mercuric thiocyanate is not a candidate for
countertop chemistry but not because it is used in detonators.

Mercury fulminate is mercuric cyanate  <Hg(CNO)2> not mercury
thiocyanate.  "Pharoah's serpents" are made using mercuric thiocyanate.
The salt is poisonous and considering the problems associated with Hg
there probably are better demos.