SummaryIn the clinic of Professor Benard (Paris) we had the opportunity to examine the effects of folic acid in different cases of anæmia :2 cases of secondary anæmia by hernia diaphragmatica of the stomach.1 case of Hodgkin disease with severe anæmia.1 case of subacute nephritis with anæmia.1 case of chronic nephritis with anæmia.1 case of lymphatic leukemia.2 cases of myeloïd leukemia.3 cases of pernicious anæmia.No case of secondary anæmia has successfully reacted to the treatment. Never did the reticulocytes or the red bloodcells increase. On the contrary the results were amazing in the three cases of pernicious aæmia : the reticulocytes increased between the seventh and the eighth day of treatment with a maximum of 40 % in the first case;4,8 % in the second and12,8 % in the third case.Tbh increase of the red bloodcells always followed that of the reticulocytes The first patient had on arrival to the hospital 1.240.000 red bloodcells; this count reached 8.070.000 on the 15thday and 4.280.000 on the 35thday. After 18 days the blood count passed from 2.810000 to 4.150.000 in the second patient.The third patient is still treated : his blood count passed from 1.800.000 to 2.260.000 after seven days.These few cases illustrate once more the high specificity of folic acid in pernicious anæmia Administration of the dosis after a first reticulocytic crisis had been obtained, did not produce a further increase of the reticulocytes or of the red bloodcells. An increase of the white count was also noticed.It is still too early to pronounce about the evolution of those cases treated by this new method.