[LokisMischief] wrote in to the tip line to let us know about this incredible home made CO2 laser ... hand blown glass for the laser tube, plumbing store mirror mounts, a PVC cooling jacket ...
To the first gas jar/test tube insert a lit splint – record your observations. To the second gas jar/test tube add 1 cm 3 of limewater, stopper and shake – record your observations.