If it's highly-cut, then this number will be about ten degrees lower by the time it's fully solid. If it's pure, this temperature should not change much at all during solidification.
Pure methamphetamine should begin crystallization between 170˚C and 175˚C, and with cut methamphetamine this would happen at a lower temperature. As soon as it starts to form crystals, make a note of the temperature. Wait for it to all melt, then turn off the heat and start monitoring the temperature. Eventually, the stuff in the tube will melt, and when it does, insert the thermometer. The hottest part of the flame is at the tip, so no yellow or blue flame should hit that glass. Put mineral oil or cooking oil or some other clear liquid with a high boiling point in the beaker, then put the test tube in that and heat it on a stove burner or a flame or something. Its bill nye the science guy time in this bitch. Put as much of the alleged drugs in the test tube as you can. Get a glass thermometer than can measure up to at least 200˚C, a test tube, and a vial or a small beaker or something, that you can put the test tube in without it falling over.
