摘要: Abstract The electrophoretic method of introducing certain allergens into the skin is a useful reproducible technique for transporting these dermis. Giant ragweed, dwarf and timothy extracts have been employed in this way. An unit pollen dosage defined. ragweed used satisfactorily preseasonal treatment series seven cases hay fever by electrophoresis skin-reactive constituents. Analysis undialyzed extract, using both Philpot-Svensson Longsworth techniques to estimate amount skin-reactive, unpigmented constituent present, has revealed that very large fraction present extract giant ragwee. We have, 7 therefore, experimentally since they are much simpler prepare less expensive. It possible introduce quantities material from electrophoresis. Several patients treated preseasonally way New York City thus far (Aug. 27, 1940) had satisfactory season.