In 1927 Fairley Described in the Medical Journal of Australia an Intradermal Reaction in Human Schistosomiasis, Using as Antigen the Dried Powdered Livers of Snails (Planorbis Exustus), Infested with the Cercaria of Schistosoma Spindalis of the Goat, Dissolved in Saline. The standard dose adopted was 0·25 cc. of an 0·5 per cent, extract prepared from the dried powder, ground up in a mortar with 50 ccs. of normal saline solution (0·85%) and the resulting mixture thoroughly shaken by hand. It was then incubated for one hour at 37° C. Subsequently the extract was centrifuged, the supernatant fluid pipetted off and filtered through a Seitz filter (size 3) attached to a water pump. The filtrate, consisting of a clear coloured fluid is put up in ampoules of 0·5 cc. each and stored in an ice-chest.