However, your editorial suggestion that popular education rather than drastic legal enactments should be employed to secure a reasonable standard of health preceding marriage, is undoubtedly sound and should lead to what ought be the much-desired condition. Legislation, here as elsewhere, is not the panacea of all the matrimonial ills of which we know. But silence is an inexcusable crime in the premises. DUANE MOWRY MILWAUKEE, WISCONSIN _The Fourth Dimension_ [TO THE EDITOR OF THE FORUM] DEAR SIR,—With due deference to your valued journal, the article of Claude Bragdon, _Learning to Think in Terms of Spaces_, in your August number, is essentially illogical. The writer thus introduces his subject: “A point, moving in an unchanging direction, traces out a line; a line, moving in a direction at right angles to its length, traces out a plane; a plane, moving in a direction at right angles to its two dimensions, traces out a solid. Should a solid move in a direction at right angles to its every dimension, it would trace out, in four dimensional space, a hypersolid.” Now this may pass current in blackboard geometry, but does not hold good in the abstract. The physical point is indeed extended to represent the line, and the physical line, to represent the plane, etc. But these concrete objects are not to be conceived as true geometrical figures, which are not movable, for motion presupposes sensuous experience. Only matter is movable. The true geometrical line is not the extension of the point, nor is the cube formed by the extension of the plane. When a point “moves” it is no longer a point, and when a cube “moves” it becomes annihilated. “Student,” in a letter upon the same subject, speaks of a division of a cube into smaller cubes. But when a part of a geometrical figure is conceived the first figure is of necessity annihilated.