“The PENETRABILITY COEFFICIENT resulted as follows: A 5 per cent. solution of phenol killed _Bacillus coli_, suspended uniformly throughout a cylinder of 1.2 per cent. agar in the interval between 60 and 90 minutes. A 1 per cent. solution of phenol killed the same organisms under the same conditions in the interval between two and one half and three hours. An undiluted solution of Trimethol Syrup killed the organisms in the interval between two and one half and three hours. A 10 per cent. solution (nine volumes of distilled water to one volume of Trimethol Syrup) failed to kill the organisms in four hours. It would appear that undiluted Trimethol Syrup has the same combined penetrability and germicidal value as a 1 per cent. phenol solution. “The PHENOL COEFFICIENT: A 10 per cent. solution of Trimethol Syrup in distilled water (nine volumes of distilled water to one volume of Trimethol Syrup) possesses the same germicidal power as a 1 per cent. solution of carbolic acid. This coefficient takes no cognizance of the _actual amount of Trimethol as such_--it merely indicates the relative germicidal power of the Trimethol Syrup as sold.” The preceding report shows that Trimethol Syrup has a phenol coefficient of 1/10, and, assuming Trimethol Syrup contains the amount of Trimethol declared, the substance Trimethol would have a phenol coefficient of 8-1/3 instead of 40, as is claimed. According to Kendall and Edwards’ method, the penetrability-germicidal value of the syrup is equal to a 1 per cent. solution of phenol. WALKER’S REPLY TO CRITICISM The report of the bacteriologist was submitted to The Walker-Leeming Laboratories for comment. The following reply was received from J. T. Ainslie Walker: (_May 22, 1917_) “In reply to your letter of the 15th inst., which has just been placed before me on my return to town, I have to inform you that the potent constituent of Trimethol Tablets and Trimethol Syrup is not fully available as a bactericide until it comes in contact with the pancreatic fluid. “As you will see from the enclosed extracts from clinical reports, the therapeutic value of Trimethol has been well established.