The Haemolytic Acid present in Horse Brain 2. EXAMINATION BY THE INSOLUBLE MONOLAYER TECHNIQUE BY E. D. GODDARD

The results obtained in Part 1 of this investigation (Morton & Todd, 1950) have indicated as the structure of the haemolytic acid a straight chain monobasic fatty acid of 18 carbon atoms, containing one unsaturated bond ofthe ci form. Because ofthe small amount of the acid available, elucidation of its structure by degradative studies was rather difficult, and therefore some physical approach to the problem was sought. A compound ofthis type would be expected to lend itself readily to investigation by the insoluble monolayer technique and, as will be shown below, considerable information as to the structure of the acid has in fact been obtained by this means. EXPERIMENTAL