On injecting a neutral solution of pure trimethylamine oxide into two quarters of an udder, the quarters increased in turgidity up to 2·5 hr. and then relaxed. The oxide diffused rapidly out of the quarters during the third and fourth hours after injection and a maximum concentration was shown in the urine at the end of the third hour. In a period of 8·3 hr., 76 % of the oxide available for diffusion was recovered from the urine.

The milk obtained 7 hr. after injection contained 7–8 mg. % of tertiary nitrogen, but the secretion had not in that time regained normal composition owing to the interference with the natural functioning of the quarters.