Collected Papers, Cross-reference index:
Contributions to The Century Dictionary and Cyclopedia; first edition, 6 vols., The Century Co., New York, 1889-1891.
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The following notes from Peirce’s personal copy are reprinted in Collected Papers: on pragmatism (c.1902), 5.13n1; on the continuum. 6.165168. (6.164n* assigns a date of 1903 to 6.165-167 and does not identify 6.168. The dating in Peirce’s copy is not clear, but it seems to the editor that “Sept. 18, 1903” applies only to 6.168 and not to 6.165-167.)