Purchase the Pyrex test tube, rubber cork with hole and Pyrex tube all out of a single set. They need to fit with an airtight seal: cork in the test tube, and tubes within the holes of the cork.
Push the one of the Pyrex glass tubes through the cork. The tube should barely stick out through the other side of the cork.
Push the second glass tube deep into the cork. When the cork is placed in the test tube, the Pyrex tube should have roughly 1 inch of room to the bottom of the vial.
Fill the bottom of the test tube with 1/4-inch to 1/2-inch of tobacco. Fit the cork stopper firmly in place.
Heat the tobacco with a lighter by brushing the bottom of the test tube with the flame. The vapor will be very light colored smoke.
Inhale the vapor through the longer glass tube.