For the study of variability of the action of hydrolase in animal organs under intoxication with hypnotics, the author has undertaken an experiment in determining the activity of various kinds of hydrolase, i.e., cathepsin, phosphatase, amylase, arginase, asparaginase and urease found in the brain, liver and kidney of guinea. pig which were died of intoxication, under deep hypnosis and awakened from hypnosis by administering with Diethylbarbituric acid (Veronal); Ethylhexabital calcium (Adorm) and Ethylcarbamate (Urethane), injected intra-peritoneally; and the values compared with the normal guinea pig.