The Trimethol “literature” does not throw light on the question, What is the germicidal value of Trimethol Syrup as compared with phenol? The only available method of determining the germicidal value of a liquid disinfectant is to make a direct comparison of the substance in question with phenol under similar conditions. Given parallel conditions, not obviously prejudicial to the substance tested in contrast to the standard solution, the results are comparable, and furnish a basis for estimating the relative germicidal power of the two substances. In the investigation, Trimethol Syrup and phenol were thus compared. As regards the contention that the bacteria within fecal masses are harmless, this may be granted. But it must also be admitted that these intestinal masses are constantly being reformed so that buried micro-organisms do not remain in the interior. For this reason, the determination of the penetrability coefficient of a germicide is pertinent. Regarding the respective merits of the old Rideal-Walker and the newer U. S. Hygienic Laboratory method of determining the phenol coefficient, the Rideal-Walker method was found to possess certain drawbacks, and in an attempt to overcome these the “_Lancet_ Method” was evolved; this method in turn was improved in the U. S. Hygienic Laboratory and led to the United States Public Health Service Hygienic Laboratory method for the determination of the phenol coefficient of disinfectants (published in _Hygienic Laboratory Bulletin 82_). In 1913 this method was formally adopted by the Council for the valuation of disinfectants or germicides of the phenol type, and the method is now in general use for this purpose in the United States.[119] In this connection Hiss and Zinsser may be quoted (Ed. 2, page 80): “The most precise method of standardizing disinfectants is that now in use in the United States Public Health Service.” Stitt, director of the United States Naval Medical Schools, in his Practical Bacteriology, Blood Work and Parasitology (Ed. 4, page 473) says: “In the United States disinfectants are rated according to the Hygienic Laboratory Phenol Coefficient.” [119] Those who are interested in the relative merits of the Rideal-Walker, the _Lancet_ and the Hygienic Laboratory methods for the valuation of disinfectants, should read the following: Method of Standardizing Disinfectants with and without Organic Matter, J. A. M. A., Aug. 24, 1912, p. 667; Standardization of disinfectants, Report of the Council on Pharmacy and Chemistry, J. A. M. A., April 26, 1913, p. 1316; Standardizing Disinfectants, J. A. M. A., Sept. 30, 1916, p. 883.