Page:Popular Science Monthly Volume 24.djvu/661

Rh pneumogastrics—two nerves arising from the lower portion of the brain, near the base. Now, the thinking portion of the brain being situated on the convex surface, deep and perplexing thought robs the roots of the pneumogastric nerves of their circulation, and in this way depresses their influence. Lacking the proper nervous stimulus, the digestive juices become scanty in amount; peristalsis is enfeebled; the liver—that refinery where the crude products of digestion are purified and elaborated loses tone, and allows the peptones to pass unchanged into the general circulation, giving rise to much discomfort and mental depression. Thus are laid the foundations of dyspepsia, that common complaint of students; and in the higher institutions of learning, where the course is difficult and protracted, many, after graduation, return home invalids—often only to die.

The products of digestion are taken up by two different sets of vessels. The fatty matters, in the form of an emulsion, go almost directly to the right side of the heart; while the others, before entering the general circulation, pass through the liver. A portion of the refuse is excreted here; the rest, remaining in solution in the blood, is carried to other organs to be gradually eliminated. So that, during digestion, the blood is not only charged with impurities from the alimentary canal, but also with newly or imperfectly formed material.

The brain, then, being deprived of its full blood-supply, and the blood itself being impure and impoverished, it may at once be seen that the mind is not very active after dinner, and by no means fitted for severe study. Hence the lighter subjects—reading, geography, history, writing, drawing, music—should occupy the afternoon session, as these subjects involve chiefly the imitative faculty and the memory. Of these, reading and music—the lightest of all—should precede; dictation and geography may follow. When the programme includes an afternoon recess, history may follow with advantage. The most appropriate time for writing and drawing is from half-past three to four. The muscles of the hand are steady, the pupils are fatigued mentally, and the imitative faculty—the lowest in the scale—is the only one called into play.

Two o'clock may be set down as the most judicious time for the opening of the afternoon session. Half-past one is not quite so good, but will answer very well. To begin at one is a positive detriment. The pupils hurry home, snatch a hasty dinner, and as hurriedly return. Those who dwell at some distance are often late. Some are obliged to attend to household duties, and this also occasions tardiness. Sunlight is cheap and plenty, and the half-hour gained would be more useful if taken at the end of the session. Indeed, two hours' steady work will exhaust the majority of children, and will leave all seriously disinclined to exertion. When school assembles at two, and is dismissed at four, no recess is necessary, if the plan here indicated is followed, for the work is much lighter than during the morning session.