THE USE AND ABUSE OF ANTIBIOTICS

been able to keep ahead of pharmacological progress by becoming resistant to each new antibiotic that has been introduced. Until recently we have been able to keep the situation under partial control because new antibiotics have generally appeared in time. But we are now face to face with the third disadvantage of antibiotics. That despite the multiplicity of names given to them, there are in fact very few antibiotics. Indeed not more than about a dozen all told. This paucity is due, fundamentally, to the fact that antibiotics come from moulds, and it is only the very exceptional mould that can produce a useful antibiotic at all. Indeed tens of thousands of moulds must have been examined to find the 12 which produce antibiotics that are of value. It is, therefore, wishful thinking to assume that many more antibiotics are likely to become available from naturally occurring moulds in future years. Nor are we entitled to assume too readily that the chemists will come to the rescue and evolve new antibiotics in the test tube for use in the immediate future. Thus we are faced with a situation that is, as far as I know, completely new to medicine. That with a very limited number of therapeutic sub727