“…They point out now, however, that the relative merits of butter and other fats vary according to their level in the diet (246), and the findings from another laboratory (247) agree with this view. Jansen and his collaborators remain of the opinion that summer-pasture butter possesses a value not shared by other fats (248,249), but papers (233,235,236,238,239,240) specifically deny this, and work reported in (250) discloses no superiority of milk fat over lard. Whatever the outcome of this controversy, there is now complete unanimity that vaccenic acid is in no way involved, being quite inactive (233,235,238,240,245,248,249,251,252).…”