1,189,340. Antigen adjuvant compositions. AMERICAN CYANAMID CO. 13 Sept., 1967 No. 41833/67. Heading A5B. Adjuvant compositions comprise a water-inoil or a water-in-oil-in-water emulsion, the oil being a physiologically acceptable oil, at least 0.15% w/v of a hydrated salt of a physiologically acceptable divalent or polyvalent metal and a physiologically acceptable fatty acid having from 12 to 24 carbon atoms, and an antigenic material present in a sufficient amount for producing immunologically satisfactory anti body formation. The metal may be Al, Fe, Mg, Ce, Zn, La or Bi and the fatty acid may be palmitic, stearic, lauric, myristic, arachidic, behenic, lignoceric, ricinoleic, oleic, erucic or linoleic acid, the preferred salt being aluminium monostearate. The oil may be peanut, safflower, soy bean, cotton seed, corn, chaulmoogra, olive, sesame, coconut or light mineral oil. The composition may also comprise an emulsifying agent of the type which favours formation of oil-in-water emulsions e.g. polyoxyethylene sorbitan monooleate. The antigenic materials may be derived from viruses e.g. influenza and foot and mouth antigens; mickettsia; bacteria e.g. tetanus toxoid; polysaccharides e.g. pneumococci, tumours allergic materials e.g. pollens, dust, danders and extracts thereof such as rag weed, house dust, pollen and grass extracts; and poisons or venoms of bees, wasps, poisonous snakes, scorpions and Lactrodectus mactans.