1. Experience of addicts and observations upon them show that the length of time over which an addiction sufferer is free from his “withdrawal” manifestations is in proportion to the amount he has recently taken. Under conditions eliminating various factors, outside of the addiction mechanism, which may influence this general rule, the ratio between the amount of recent dosage and the interval of freedom is almost mathematical. For example, if under given conditions one grain of morphine will keep an addict free from withdrawal manifestations for four hours, two grains will do this for nearly eight hours and three will have the same effect for about eleven hours. It would almost seem as if there were some substance produced in definite amount in each individual case at a given time, and neutralized or opposed by or in some way negatived in its action by a definite amount of opiate drug. 2. Each addict shows a definite and approximately measurable daily minimum need for the drug of his addiction. If he is suffering from the deprivation of his drug, he will require a certain dose, measurable by its effect upon his symptomatology, before he is made physically comfortable and physically efficient again. 3. The narcotic drug administered to an addict suffering withdrawal phenomena and symptomatology will relieve those manifestations exactly in proportion to the amounts of drug administered. Each addict has a constant sequence of symptoms attending the so-called “dying-out” of the drug. These symptoms are relieved in constant reverse sequence by the administration of the drug, and in exact proportion to the amount of drug administered, various incidental influences being eliminated. A small amount of the opiate will relieve the symptoms last appearing; another insufficient amount will relieve another proportion of the withdrawal signs, and so on, until the opiate drug administered balances in amount the extent of the addict’s deprivation, or physical need. This is almost mathematical in its working, and the average intelligent addict, after a few trials, can tell within a very close margin just how much opiate, in his accustomed form, has been administered by the extent to which it relieves his withdrawal signs. It almost seems as if the narcotic drug acted as some sort of an antidote for some poison present in definite amounts in the addict’s body. CHAPTER IV THE MECHANISM OF NARCOTIC DRUG ADDICTION-DISEASE I have in previous chapters referred to what are known as “withdrawal signs.” By this term has come to be known the manifestations displayed by a sufferer from addiction-disease at such times as his opiate is taken away or “withdrawn,” either totally or in part to such an extent that its amount does not meet the requirements of his physical needs.