Induction of Labour

of a mixture of two or three chemical substances each substance retains its own solubility irrespective of the amounts of the others which may be present; and the antibacterial activity of a combination of sulphonamides is additive. It is thus possible to give two or three sulphonamides together, each in a dose less than that usually regarded as effective, yet with a consequent reduction of the risk of dangerous crystallization and with the total combined dose therapeutically adequate. Nevertheless it is cheaper to prescribe sulphadimidine alone in adequate doses, and the danger of crystallization using this sulphonamide is minimal. The desirability of combining penicillin in polypharmaceutical preparations is questionable. It is usually undesirable to use " shot-gun " prescriptions and it is impossible to increase or decrease the dose of one ingredient without increasing or decreasing the dose of the others.