Red ink makes good colouring matter.
Make touch-paper by soaking any porous paper in a solution of saltpetre, and drying it.
Instead of bending glass tubes, join them with rubber tubing.
To make a test-tube holder, fold a sheet of paper until it is about half an inch wide and wrap this around the tube.
To bend glass tubing, hold in the flame of the spirit-lamp and rotate between the fingers till it becomes soft and flexible, remove from the flame, and bend.
To break glass tubing, first scratch with a file.
To break glass bottles, make neatly a deep cut with a file, then touch the glass near the cut with a red-hot wire. When a crack appears, move the hot wire and the crack will follow. Several heatings may be necessary.
In the case of a heavy glass bottle, file the cut as before, wrap the bottle with string dipped in alcohol, light it, and after it has burned, plunge the bottle vertically into cold water.
Melted paraffin is good for closing small leaks.