摘 要 沈寵綏在《度曲須知‧方音洗冤考》中設法替北音洗冤。他從各種書證中 證明下列的讀音才是正確的：(1)「寧、年、娘、女」聲母讀n，不讀吳語的¯。 (2)「昂、訛、遨、傲」聲母讀零聲母，或是吳音的[˙˙]，不讀吳語的N。(3)「忘、 無、文、萬」聲母讀零聲母，不讀吳語的v。(4)「微、圍、未、慧」韻母讀ui， 不讀吳語的i。雖然他以反切系聯來追索讀音來源的作法，值得喝采，他的基本 觀念和論證過程仍有許多值得商榷的地方。本文以方言和音韻史作為參照，對 沈寵綏〈方音洗冤考〉的是與非，分別進行了檢討。

Abstract In a chapter of his monumental work “Instructions of Composing Chu Poems”, Shen Chongsui tries every effort to demonstrate that in the following competing readings the former ones which represent the Northern Mandarin, rather than the latter ones which represent the Wu dialect, are correct. (1) n:¯. (2) O(<*N):N. (3)O(<*mj):v. (4) ui:i. While his methodology, i.e. so-called “Threading method”, is reasonable, his argumentations are full of fallacies. Evidences from the history of Chinese Phonology and dialectology are given in this paper to show the right and wrong of Shen Chongsui’s theory.