One of the most interesting phenomena ih the trend of our modern therapeutics is the present extensive use by physicians of the variously medicated clay mixtures as external applications in the treatment of pneumonia, bronchitis, pleurisy, rheumatism, synovitis, boils, etc., in place of the cotton jacket, mustard and flaxseed poultices, blisters, cupping, camphorated oils and hot stupes. By a clay mixture I mean any one of the various proprietary preparations which are said to have an antiphlogistic action in inflammations of superficial and deep structures. The essential composition of all such clay mixtures is a base consisting of silicate of alumina and magnesia combined with salicylic acid, peppermint, wintergreen, eucalyptus, iodin or ammonium iodid and iron carbonate. The glycerin is added to give the kaolin or white clay its thick, jelly-like consistency so as to allow of easy spreading, while the other substances are added for whatever