Crystalline Hæmolytic Substance from Normal Blood

THE occurrence of a haemolytic substance in normal blood has been demonstrated by Bergenhem and Fahraeus1. This substance was present in the ether precipitate of the alcohol-soluble fraction of serum, and was described by them as a lysolecithin, that is, a derivative of lecithin from which one fatty acid has been split off by the action of lecithinase, an enzyme analogous to that contained in cobra venom. However, the evidence in favour of the existence of lecithinase in serum and of the lysolecithin nature of the lytic substance was indirect, since no attempt at purification or isolation of either the lecithinase or the lytic principle has been reported.