The subject of these tracings was a man well-known and prominent in his community, 63 years of age, suffering from pneumonia with marked and persisting cardiac and circulatory deficiency which did not respond to the administration of the usual circulatory stimulants even in very large doses. I was called in consultation. Found the patient very weak and exhausted, with facial expression of protracted suffering and anxiety and despondency. Morphine in usual therapeutic doses had been daily administered for relief of pain, restlessness and sleeplessness, being insufficient however to control those manifestations. Pulse was, as shown in tracing number 1, very weak and intermittent. It was impossible to account for the whole clinical picture and history on the grounds of a typical pneumonia, present or resolving. Opiate addiction was suspected and the patient questioned. He had been suffering from opiate addiction-disease for many years, his addiction developing unsuspected by him as a result of medication for a painful and protracted condition many years previous. He begged to be allowed to die without his wife and son being told of his affliction. The following tracings made upon him are very instructive and significant, and cannot be interpreted upon any grounds of psychical explanation of addiction phenomena. The last dose of morphine prior to these tracings was one-eighth of a grain given at 3:30 P. M. [Illustration: (Chart of Sphygmographic Tracings)] First tracing (number 1) was made about 6:00 P. M. Tracings 2, 3 and 4 were made at about fifteen minute intervals. They were made following experimental hypodermic injections of morphine sulphate to determine the extent of opiate need and organic dependence upon opiate medication, and the amount of opiate required to restore organic function and tone. Tracing number 4, taking into consideration the asthenic and exhaustion condition of the patient, shows full support to circulation with some overaction. Tracing number 5 was taken an hour or two after tracing number 4 to determine the holding power of the dosage administered, after the circulation had reacted from the immediate stimulation of the opiate medication. This tracing, interpreted and considered together with the clinical manifestations at the time, was decided to be about normal for that patient at that time. This patient would have died, not from pneumonia with cardiac complications, but from insufficient control of the mechanism of opiate addiction-disease. On balanced and indicated daily morphine dosage, patient made very rapid recovery and has continued well and active.