There are three clinical demonstrable elements to be determined, measured and controlled in the actual therapeutic handling of cases of narcotic addiction-disease. The first of these is the actual amount of drug which the patient’s body demands to maintain functional and organic efficiency and to escape physical distress. The second of these is the extent of auto- and intestinal-intoxication, autotoxicosis and malnutrition. The third of these, which is both a result of and a causative element in the other two, is the extent of inhibition of function. In the successful handling of a case of addiction-disease, therefore, the first effort should be to determine approximately the amount of the patient’s minimum daily physical need for the drug of his addiction. This need is clinically recognizable and definitely measurable. It should be met to whatever extent it is present so long as it exists, and dosage diminished only as competent treatment diminishes the extent of need. This physical need can be demonstrated and accurately measured by clean-cut symptomatology. It can be expressed in mathematical terms of amounts of drug required in twenty-four hours. Work, worry, strain--anything which consumes physical or nervous energy increases this need. If this physical need is not met the patient is robbed of physical tone and physical reaction. He is robbed of metabolic balance and functional competency. He is, in short, robbed of the basic ability which his body has to regain health. In the estimation of this amount of physical need the procedure is very simple. Have administered to the patient who is manifesting the symptomatology of drug-need, sufficient drug to remove the symptoms and restore him to complete physical, functional and nerve balance. Have the length of time observed which elapses before the symptoms of drug need reappear. Have this repeated several times and information is secured as to what quantity of opiate under the existing conditions will hold that patient in drug-balance for a known length of time. In this way can be mathematically estimated the extent of physical drug-need. The average need for twenty-four hours can be easily computed from the data obtained. It is merely a matter of arithmetic. The regulation of dosage can also be estimated with approximate accuracy. As has been stated before, the interval of freedom from withdrawal manifestations is found to be, in a general way and within certain limits, in ratio to the size of the dosage. For example, if in a given case, under given conditions of fear, worry, physical or nervous strain, pain, etc., as discussed elsewhere--one grain of morphine will last a given patient at a given time for four hours; under the same conditions two grains will last for approximately eight hours. There are limits to the application of this rule. It is stated as the general operating of an addiction-disease phenomenon which is useful as a therapeutic guide.