If they are not able to carry a line of mental work covering a period of two, three, or five years, as the case may be, they should be told this, and counseled to spend their summer vacations in working in the open air; or, if unable to stand the strain of constant schoolwork, they should be counseled to spend much of their time in outdoor work, and to study books by themselves. If they are careful to exercise sufficiently, the brain will be clear to grasp the subjects that they study alone, and their progress will be rapid. Let them endeavor to treat the sick, as they have opportunity, putting into practice the theory that they gain from the study of books. I have been instructed that in many instances more practical knowledge can be obtained in this way than by a long course of study in a medical school.— Manuscript 123, 1902.