Just a note because I see that some have confused the two in the preceeding discussions. !!!! DO NOT confuse Benzine (Naptha, white gas, Coleman Fuel) with Benzene.
http://www.bt.cdc.gov/agent/benzene/basics/facts.asp
http://www.eco-usa.net/toxics/chemicals/benzene.shtml
http://www.hse.gov.uk/pubns/indg329.pdf The old Bergman recipe calls for Benzine NOT benzene. That's flamable but not considered to be a major health threat.