Although cases of skin hypersensitiveness to procaine hydrochloride have been reported, in only a comparatively small number has the blame been absolutely fixed on this substance by means of skin tests, as, for instance, in the cases reported by C. Guy Lane.1Lane found that, in two patients suffering from a dermatitis of an erythematous papulovesicular type, the chance spilling of procaine on the skin while performing the scratch skin test caused an eczematous skin reaction to appear the following day. The skin eruption was limited to the area on which the procaine had been spilt. In Lane's cases the scratch test for immediate wheal formation was negative. This is in accordance with what has been recently noted as being the case in dermatitis of the eczematous type. The scratch test is usually negative but the contact test is positive. In the case of Galewsky,2dermatitis due to