FROM THE PRESIDENT OF THE UNITED STATES:
(Thefollowing letter has been made pubk by the Federal Security Agency, and we think it important..aough to print in full.) Mv dear Mr. Administrator: Keports have reached me that some young people who had planned to enter college this fall, as well as a number of those who attended collee last year, are intending to interrupt their education a t this time because they feel that it is more patriotic to work in a shipyard, or to enlist in the Army or Navy, than it is to attend college. Such a decision would be unfortunate. We must have well-educated and intelligent citizens who have sound judgment in dealing with the difficult problems of today. We must also have scientists, engineers, economists, and other people with specialized knowledge, to plan and to build for national defense as well as for social and economic progress. Young people should be advised that it is their patriotic duty to continue the normal course of their education, unless and until they are called, so that they will be well prepared for greatest usefulness to their country. They will be promptly notified if they are needed for other patriotic services. Sincerely yours, FRANKLIN D. ROOSEVELT TAE W ~ HOUSE B WASAINGTON
A SIMPLE EXPERIMENT ILLUSTRATING DIFFUSION JOHN H. GARDNER Washington University, Saint Louis, Missouri
AS A means of rendering'dilksion visible to a class of students, a test tube containing solutious of colored salts in a succession of layers has frequently been used. The execution of this experiment requires considerable care and the tube, when prepared, must be carefully protected from agitation if the experiment is to be a success. If gels %reused instead of solutions, very much less manipulative skill is required and the finished tube is not affected by agitation in handling. A simple form of such an experiment has been devised. A test tube is filled to a depth of about five centimeters with a clear gelatin solution which is allowed to set to a rigid gel. About an equal amount of the gelatin solution colored intensely red by the addition of a small crystal of fuchsine is then poured into the tube and allowed to set. The colored gel is then covered with a layer of paraffin to prevent putrefaction. In about an hour a noticeable diiusion of the fuchsine into the colorless layer will have taken place, the penetration continuing at a diminishing rate for several days. At all times, the original line between the colored and colorless layers remains visible.
