EDUCATION

DEVOTED TO THE SCIENCE, ART, PHILOSOPHY AND

LITERATURE OF EDUCATION.

VOL. XIII.

JUNE, 1893.

MEASUREMENT OF BRAIN WORK.

SUPT. J. M. GREENWOOD, KANSAS CITY, MO.

No. 10.

VERY great impetus was given to scientific investigation. by the doctrine of the conservation of energy as used in the physical sciences. Joule showed first that heat can be measured in units of work, and Tyndall, acting upon Faraday's suggestions, ascertained that heat, light, and electricity, are only modes of motion. With these discoveries it then becomes necessary to reconstruct all the prevalent ideas entertained in regard to the measurement of force in its various forms. The physicists, thus surprised and delighted, saw a new field to be occupied; the mathematicians devised a new algebra and geometry to meet the demands of this sudden extension in scientific investigation. Ohms, volts, amperes, and other electrical terms no longer the special property of the occult few, grew into daily use as familiar words in many households. Energy, or the capacity for doing work, was given a wider meaning than it ever had before. The tendency to measure forces of all kinds in powers of working units manifested itself in all the physical and biological sciences. To change the place or form of energy, the power necessary to do it was estimated in units of work.

To apply this method of investigation to the process of thinking, was conceived as the only correct way of determining the molecular changes in the brain substance itself. Heat, light, electricity, being modes of motion, thought must also be a mode of motion, produced by the vibrations of the brain substance.

If so many tons of coal by setting free the potential heat it contains is converting water into steam, and the steam exerts a force sufficient when utilized to haul a train of cars from St. Louis to Kansas City, why would not the food and drink that a human being takes into his system during a day, be the right basis for estimating his thought producing power. A possible physical method of recording thoughts as the result of the molecular changes in the brain cells, corresponding to the molecular changes in matter as registered, appears both plausible and probable.

Men have always studied the phenomena of things more distant from themselves than of those not so remote. Chemistry and electricity in their modern aspects and future possibilities, had not been born when celestial mechanics was far advanced upon a strictly scientific basis. Such has been the wonderful progress in physics, chemistry, and electricity that many have become somewhat impatient, because the instruments of measurement employed in estimating the forces liberated in these sciences, can not give accurate data in foot-pounds, volts, farades, ohms, coulombs, ergs, or dynes, in terms of mental phenomena. Yet the effort to find a common measure for these material sciences in terms of thoughtforce, tends to illustrate the demand to obtain equivalents in mind work for the amount of food material consumed by the body.

In another form, the energy expended by the teacher in instructing children should appear in the children in another equivalent form without any loss by transmission whatever. To measure an immaterial product by a material unit, is the thought-form of the mind trained under the present system of exact dealing with energy as it is converted from one form to another. This is the physical basis of life and thought.

If it be admitted that physical energy is the ability to do work, whether it be physical or mental, then it becomes a school question of the first magnitude, when it is proposed that teaching shall be done with the least economical expenditure of brain and nerve force. Chemistry, in explaining its own operations, assumes that material phenomena must be explained by other material phenom

ena.

In material things, force is revealed through energy; but mental movements undoubtedly originate differently. The strength of a thought in a teacher's mind may make no perceptible impression whatever on the mind of a child, and if the con

ditions be changed, the mind energy of the child may, or may not, affect in the least the teacher's thoughts. The one is not always, indeed seldom is, a correlation of the other. All good teaching, which depends solely upon the correlation of mind forces between the teacher and the learner, implies that both must pass imperceptibly into sympathetic relations. Each mind is a center of force within itself, and this is the reason why power, force, or energy, cannot be transferred from one mind directly to another. This statement may need to be explained, and while there is always more or less liability to confusion in drawing parallels between physical objects and mental modes of thinking, yet it often occurs that simple illustrations, or concrete examples, help to make abstract propositions simpler and easier of comprehension. If we suppose a dry goods merchant decides to give his attention to one line of his goods, and that he neglects all other branches of his business, people would call him short-sighted, and for the obvious reason that his view of business is too restricted. Again, suppose a farmer owns a fertile farm, every acre of which produces excellent crops, and that he has hands and implements to till every foot of it, but he prefers to let nearly all of it grow up in weeds, while he raises a small crop on a very insignificant part of his farm. People, then, would call him short-sighted. In both cases the merchant and the farmer fail to work all their business. In a similar manner a teacher may exercise only a fractional part of the child's brain area, and the remainder goes to waste. Large areas or brain tracts lie uncultivated. The illustrations are analogous and the same principle underlies all three cases.

THE HUMAN BRAIN AS AN INSTRUMENT.

There does appear to be some connection, other conditions being equal, between the size and quality of the brain and mental power. But even here there is nothing yet absolutely certain. The human brain has been partially explored, as it were, and only very small areas mapped out by Ferrier, Hulings, Jackson, Wundt, Exner and other able physiologists.

At birth the brain of the infant is about one-tenth the weight of the body, and for the infant of medium size, the brain weighs from ten to twelve ounces. By the end of the second year the body has grown so rapidly that the brain is about one-fourteenth of the weight of the body, and by the end of the third year one

eighteenth. At six the child's brain has attained about eightyfive per cent. of its adult size, and the child is now able to use it with about as much precision as it uses its hands and feet. The brain now continues to increase in size very gradually till middle life when it begins to diminish at the rate of one ounce in ten years. It is only in the most indefinite and general way that it can be claimed that growth of the brain in size corresponds with the development of the physical life.

The difference, too, in the sizes of the human brain, is a matter of more than passing interest. Byron's brain weighed about 79 ounces; Cromwell's, 78.8 ounces; Cuvier's, 64.5 ounces; Webter's, 53.5 ounces; Gauss', 52.7 ounces. The average weight of the brain of the European male is from forty-six to fifty-two ounces, and of the European female from forty-two to forty-six ounces. Many men of rare intelligence and great executive ability have been found to have brains much below the average size; also many men of enormous heads display no mental ability whatever. Even the tests by convolutions do not always harmonize, and one side of the brain is never a counterpart of the other.

Dr. Jacobi, on the development of the brain in children, says: "Between the fifth and sixth years the base of the brain grows very rapidly; the frontal bone protrudes anteriorly and grows upward. The anterior portion grows considerably, but still the white substance in the middle portion of the brain is prevalent. These are the organs for the receptive faculties and memory. About this time learning ought to commence in earnest. The gray substance of the brain begins now to develop rapidly, and the brain needs constant exercise, but not severe enough to fall below the fatigue point.

An error in Dr. Jacobi's statement needs to be pointed out. He should have included the reflective faculties, for nearly all children long before the sixth or seventh year is reached, exercise their reason constantly. An omission of this kind, that is, of not interpreting the child's thoughts correctly, has led many physicians and others easily disposed to draw hasty conclusions into the greatest extravagancies and inconsistencies. From a clearer understanding of the whole subject of the child's growth and mental power, the German medical authorities are practically unanimous "that children have no business to begin to learn before they are six years old." American physicians are vague on this point.

The very fact that mental states cannot be estimated by units of work like physical, chemical, and electrical substances, is sufficient within itself to frustrate all our efforts of finding a mental parallel to the persistence of force. There is no mode of passing from the one into the other in mental phenomena. No one yet has reached any standing position from which to estimate the striking force of an idea, although as much in a physical way as has been determined, is a chemical change in the excretions of the bodily organs. No scientist has so far discovered a method of reducing physics, chemistry, electricity, biology, and psychology to a common denominator. The size and weight of a brain may be estimated tolerably accurately from the capacity of the cranium, but beyond this, nearly everything else is guess-work, mere speculation, if a few not very well defined localized functions of brain areas be excepted. The entire subject has been pushed a little farther back - that is all.

THE

THE ACQUISITION OF POWER.

PROF. A. REICHENBACH, COLLEGEVILLE, pa.

HE object of this paper will be best accomplished by sacrificing an exhaustive discussion of one of its phases to a limited and suggestive discussion of a number of them, including some that appeal more or less to the experience of sense-perception.

The word power is derived from the French word pouvoir, which is derived from potere, a word from the Neo-Latin, spoken in France prior to the ninth century, and potere is derived from the classic Latin posse. The Latin word is a verb meaning originally to be able; but the French word is a verb or a noun, the former meaning, primarily, to be able, and the latter, ability or the faculty to perform. From the idea of ability we pass to the idea of exertion or action. The word power thus acquires an active and a passive meaning, and it may be regarded as including force and strength. Viewed in this way, power is a generic term; but the inability of scholars to fathom the nature of power appears in the statements that power is force in action and that force is active power. A scientific definition is, therefore, out of the question. Power is said to differ from force in having relation to