Carl Darling Buck was – and still is – a well respected scholar of comparative linguistics. Primarily a scholar of classical language, he published on Italic and Greek dialects and is most famous for his Dictionary of Selected Synonyms in the Principal Indo-European Languages and Grammar of Oscan and Umbrian. In this essay he disscusses Brugmann's law (Proto-Indo-European o in non-final syllables became a in open syllables) in the context of Sanskrit literature. This paper illustrates both the need for this rule and the reasons why it gained acceptance with so much difficulty, and linguists will find it an interesting piece.