To the Editor: To suppress the mounting hysteria and prevent the wholesale slaughter of Chinese-restaurant owners, we feel impelled to present a preliminary communication on the etiology, psychopathology and clinical pharmacology of the variously misnamed post-sinocibal syndrome (Chinese-restaurant syndrome). This reaction although first described in the technical literature in your columns has been, in fact, well known for many years to experienced allergists and Chinese-restaurant owners.The reaction is brought on in susceptible subjects by monosodium glutamate (supplied to Chinese restaurants as Accent, as Ajinomoto powder or as monosodium glutamate, C.P.). Five gm of material is adequate to produce a . . .