The Corpus Luteum Hormone. II. Methods of Extraction

1 N PREVIOUS papers (Weichert, 1928; Hisaw, Meyer, and Weichert, 1928; Hisaw, 1927 and 1929) several physiological properties of extracts prepared from the corpora lutea of the sow were described, and a few of the chemical characteristics were also briefly given (Hisaw, 1929). This paper reports in some detail the chemical procedure used in the preparation of active extracts as well as certain chemical properties of the substance, in so far as they have been determined.