Page:Popular Science Monthly Volume 36.djvu/868

  more independent." Now, why a statement like this, which is absolutely without foundation and entirely misleading, should be considered as particularly suitable for Sunday reading, we, who are not of the "Circle," can not in the least divine. It is given to the members of the Circle, however, as the utterance of a leading educator, Dr. Hill, President of the Baptist University of Rochester, and with the indorsement of Bishop Vincent, who, by selecting it, stamped it with his approval. The ordinary members of the Circle will, therefore, feel justified in accepting it without hesitation or reserve, and will form their opinion of Herbert Spencer accordingly. The wrong is done, not so much to Mr. Spencer, whose reputation is established in the world of philosophy and science, as to the members of the Circle, who are made to receive a false impression of his moral teaching. If Bishop Vincent is not too busy with work of more importance, we would earnestly invite him to do one of two things—either justify the above statement in regard to Mr. Spencer or withdraw it, and that in the same columns in which the statement appeared. We affirm most emphatically that it does entire injustice to Mr. Spencer's teaching.



early times men depended upon the constant use of their physical strength to obtain the means of subsistence, and to protect themselves and their possessions against violence; during a later period, when a class had arisen whose subsistence was provided by serfs, even these were still required by custom to use their muscles in warlike exercises; at present a large and increasing portion of civilized men are engaged in occupations which do not demand bodily exertion, and much of the labor formerly done by human muscles is now performed by steam and electricity. The modern man has reveled for a time in bodily inactivity, but is now waking up to the fact that exercise is as essential to health and the enjoyment of life as sufficient food and sleep. But there are many who have not yet learned this lesson, and not all of those who are willing to take exercise have the right knowledge to secure for them its full benefits, or to protect them against its misuse. Knowledge of this sort it is the object of the present volume to supply. We do not know of any other book that explains so fully as this what goes on within the body when the muscles are used. The author first describes the process of muscular work, then explains the nature of fatigue, tells what changes in the body are produced by habituation to work, what the essential characters of the different exercises are, what results are effected by different kinds of exercise, and closes by pointing out the office of the brain in exercise. The slightest movement performed by the human machine, he says, brings into play the neighboring parts, and sometimes also more distant ones. The old soldier who said, "When I had my two legs, I used to give a splendid blow with my fist," spoke sound science. Hence an exercise may produce marked effects in a part of the body where we should not have dreamed of looking for them. The great organic functions of the body are not isolated from the work of the muscles. More blood is drawn to the working muscular masses, and this stimulus to the circulation causes the lungs to draw in a larger supply of air. It is commonly said that work produces heat in the body, but in reality the heat is the cause of the work, and is itself produced by combustion of the nutritive substances derived from our food, of the fat, and, when these are exhausted, of the bodily tissues. The waste products of this combustion clog the muscles and are one of the causes of fatigue. Breathlessness is caused by violent exercise, which suddenly increases the quantity of carbon dioxide in the blood, and makes a great demand on the lungs to eliminate the poison. The stiffness of fatigued muscles is due to other waste products, notably the urates. Overwork causes more of such products to be produced than can be excreted; hence they accumulate within the 