Sir.—I appreciate that medical researchers, other scientists, and some medical specialists will find conversion to SI units useful.1 Certain of these units might even be adopted with little complaint from the average physician. However, it seems arbitrary to foist all these units off on the general public when 99.9% of the people will obtain no benefit and merely become confused.
Calorie is a term that has become a part of our everyday language. Why substitute joule? The general public thinks that a joule is a gem. To avoid confusion, let the scientists adapt rather than vice versa. The same applies to gram and milligram, which the public has finally begun to understand and use to a limited extent. To introduce mole for mass measurement will cause confusion. The public thinks a mole is a nuisance that makes a mess of front lawns. There is no public benefit from