What characteristic action exists in opiate or narcotic drugs which gives them this power to establish the above described mechanism? It seems to me that it is, above all, their power to inhibit body function. They tend markedly to arrest metabolic processes. They inhibit glandular activity. They inhibit unstriped muscle activity and hence peristalsis. They, therefore, cause a slowing up of glandular function and intestinal activity, and of elimination. This results in an accumulation of opiate in the body. It is this constant accumulation to which the body must become tolerant by the development of some mechanism for its protection. _Autointoxication and Autotoxicosis_ It is to the element of inhibition of function also that we must look for explanation of what is by far the most important element in the immediate picture presented by most individual cases. I refer to autotoxicosis and to auto- and intestinal toxemia. The same power that locks up within the body the opiate drug, locks up the toxic products of tissue activity and tissue waste, of intestinal poisons and of insufficient metabolism. Autotoxemia itself is markedly inhibitory in its action, and contributes no little to its own increase and to the further development of narcotic disease. It is not at all impossible that any inhibiting poison constantly present in the body will some day be found to establish a mechanism of protection, similar to that of opiate addiction, and that some of the states now popularly and loosely classified under the general head of “autointoxications” will be recognized as really addiction-states, in which the body has become progressively tolerant of its own poisons. I believe that it can be demonstrated that some of the phenomena and manifestations at times observed in chronically inhibited and autotoxic individuals in whom there can be no suspicion of any opiate or narcotic element are analogous to the phenomena of narcotic addiction mechanism. It is not inconceivable that any inhibiting poison or toxin is capable of producing its own addiction-mechanism, and it has seemed to me that my own clinical familiarity with the action and reaction of narcotic, inhibiting, or addiction-forming drugs and of addiction-mechanism upon circulation, glandular and intestinal and other function has been of no little assistance in the interpretation, control and remedy of other chronic intoxications.