The explanation of tolerance and withdrawal phenomena on the basis of something akin to an antitoxin or antitoxic substance circulating in the blood of the addict, has also, like the oxidation explanation, been a subject of controversy. Hirschlaff claimed to have produced an antitoxic serum against morphine. Morgenroth failed to confirm Hirschlaff’s findings, and argued against the existence of an antitoxin. The animal experimental and laboratory work and findings, however, of such men as Hirschlaff, Giofreddi and Valenti have helped to influence the trend of modern thought towards what may be regarded as the present strong tendency in scientific conception of the physical mechanism of narcotic drug addiction-disease--an autogenous antidotal or antitoxic substance. A recent paper by DuMez of the United States Public Health Service gives a comprehensive review of the work which has been done in connection with the study of increased tolerance and withdrawal phenomena, and shows conclusively the gradual inclination of modern opinion. There is considerable literature discussing various theories and experiments and observations, which has, however, not had widespread recognition. REFERENCES Bishop, E. S., “Narcotic Addiction--A Systemic Disease Condition,” _Journal A. M. A._, Feb. 8, 1913. Marme, W., “Untersuchungen zur acuten und chronischen Morphinvergiftung,” _Deutsch. med. Wchnschr._ 9: 197-198. Kobert, R., “Lehrbuch der Intoxikationen,” Stuttgart, 2; 995, 1906. Toth, L., “Bemerkungen zur Erklärung der chronischen Morphium Intoxikation,” Schmidt’s Jahrb. 229: 135, 1891. Faust, E. S., “Über die Uraschen der Gewöhnung an Morphin” Arch. f. exper. Path. u. Pharmakol. 44: 217-238, 1900. Hirschlaff, L., “Ein Heilserum zur Bekämpfung der Morphinsucht und Ähnlicher Intoxikationen,” _Berl. klin. Wchnschr._ 39: 1149-1152 and 1174-1177, 1902. Gioffredi, C, “L’immunite artificielle par les alcaloides,” 28, 402-407, and 31, fasc. 3, 1897. Valenti, A., “Experimentalle Untersuchungen über den chronischen Morphinismus; Kreislaufstörungen hervorgerufen durch das Serum morphinistscher Tiere in der Abstinenzperiode,” Arch. f. exper. Path u. Pharmakol., 75: 437-462, 1914. DuMez, A. G., “Increased Tolerance and Withdrawal Phenomena in Chronic Morphinism, A Review of the Literature,” _Jour. A. M. A._, 72: 1069-1072, 1919.