Carbaminoylcholine chloride (doryl) does not affect the surface tension of water. Recently, we have synthesized surface-active derivatives of this compound by replacing the hydrophilic NH2 group with water-insoluble amines, e. g., di-n-butylamine (fig. 1). This change in molecular structure and surface activity reverses the effects of the drug on the intraocular muscles. While the effects of carbaminoylcholine chloride simulate those of stimulation of the parasympathetic nerves, i. e., miosis and cyclotonia, the action of the new surface-active derivatives simulates that of paresis of the parasympathetic nerves, i. e., mydriasis and cycloplegia. Synthesis and preliminary studies of the pharmacologic action of the new drugs on the eyes have been reported previously.1 A more detailed investigation of the new class of drugs is the basis of this report. It was our purpose to synthesize an improved cycloplegic and mydriatic drug for use in routine refraction and internal examination. For this