This article provides an example of a teacher's learning, since the author only became aware of the microscale technique described very late in his professional career. The technique provides a convenient method of preparing and manipulating gases on a very small scale and a relatively safe means of demonstrating reactions that would be very hazardous on a larger scale. Safety issues are stressed but it is important that anyone attempting to follow the procedures checks these. If no suitable risk assessment appears to be available, CLEAPSS or SSERC should be consulted for further advice. Teachers also need to practise the various techniques and assure themselves of their competence to carry them out safely, minimising any danger to themselves or others. (Contains 5 figures, 1 table, and 4 online resources.)