This preponderance of interest, of passion, in determining the results of a human being's working life, obtains throughout. No elementary measurement, capable of being performed in a laboratory, can throw any light on the actual efficiency of the subject; for the vital thing about him, his emotional and moral energy and doggedness, can be measured by no single experiment, and becomes known only by the total results in the long run. A blind man like Huber, with his passion for bees and ants, can observe them through other people's eyes better than these can through their own. A man born with neither arms nor legs, like the late Kavanagh, M.P.--and what an icy heart his mother must have had about him in his babyhood, and how 'negative' would the laboratory-measurements of his motor-functions have been!--can be an adventurous traveller, an equestrian and sportsman, and lead an athletic outdoor life. Mr. Romanes studied the elementary rate of apperception in a large number of persons by making them read a paragraph as fast as they could take it in, and then immediately write down all they could reproduce of its contents. He found astonishing differences in the rapidity, some taking four times as long as others to absorb the paragraph, and the swiftest readers being, as a rule, the best immediate recollectors, too. But not,--and this is my point,--_not_ the most _intellectually capable subjects_, as tested by the results of what Mr. Romanes rightly names 'genuine' intellectual work; for he tried the experiment with several highly distinguished men in science and literature, and most of them turned out to be slow readers. In the light of all such facts one may well believe that the total impression which a perceptive teacher will get of the pupil's condition, as indicated by his general temper and manner, by the listlessness or alertness, by the ease or painfulness with which his school work is done, will be of much more value than those unreal experimental tests, those pedantic elementary measurements of fatigue, memory, association, and attention, etc., which are urged upon us as the only basis of a genuinely scientific pedagogy. Such measurements can give us useful information only when we combine them with observations made without brass instruments, upon the total demeanor of the measured individual, by teachers with eyes in their heads and common sense, and some feeling for the concrete facts of human nature in their hearts.