BY ELLIOTT P. JOSLIN, MD* INTRODUCTION. So much water has run under the bridge since I wrote" With an ex-cess of fat diabetes begins and from an excess of fat diabetics die, formerly of acidosis, now of arteriosclerosis" that 1 have felt compelled to look at the problem of Fat and the Diabetic afresh. Certainly fat and the diabetic have claimed a prominent place in our thoughts in the past. In 1914 diabetic coma caused the death of more than half of our diabetics and the relation of fat to its etiology seemed so close that the colored frontispiece of lipemic blood in a diabetic monograph was appropri-ate. Then we liad only dim ideas as to how coma came on and how it should be treated, but today a coma death in diabetes strikes us all as needless and indeed unless actual coma is prevented in our respective communities our con-sciences convict us of incompetent instruction of oui" patients. A frontispiece of fat in the blood is just as much needed today and, if its connection with arteriosclerosis likewise could be solved in a decade, how fortunate diabetics would be! Who would have believed that mor-tality from diabetic coma would drop from 60 Per cent to 5 per cent in 17 years. Arterio-sclerosis now causes more than half of all dia-betic deaths. We cannot expect to lower this mortality to 5 per cent, but I do believe that We should expect in the future to prevent the average diabetic from dying prematurely from tins complication.