Care must always be exercised, though, to work out a colour scheme that harmonises, since discordant colour effects inevitably carry to the mind suggestions of discordant thinking and feeling and doing. As a first aid to the study of colour harmony—a subject which, as soon as its significance to human welfare is more generally recognised, will be taught far more systematically than at present—I recommend painstaking observation of the colour schemes developed by master artists, as shown in the paintings to be seen in the art museums of our cities; or, better still, excursions into the country, where, in the colour combinations of earth and sky, tree and water, mountainside and valley meadow, one can gain invaluable hints from that greatest of artists, Nature. On such excursions, need I add, the children should be taken along, to receive early lessons in the appreciation of true beauty. But now, while thus utilising to the full the educational possibilities opened by the suggestibility of childhood—while reinforcing the educational value of example by the educational value of a well-arranged home environment—it must also be recognised that the child’s extreme suggestibility carries with it certain dangers. As was said, the essential element in every successful suggestion is the automatic, uncritical acceptance of whatever idea is thus intruded into the mind. It goes without saying that, so long as the critical faculty remains unawakened and untrained, it will always be possible to intrude by suggestion erroneous as well as sound ideas. More serious still, there is warrant for adding that unless the child’s critical powers be developed at an early age—unless he be taught from the outset of his life how to observe accurately and reason closely—the tendency to uncritical acceptance may become more or less of a habit. That, under present conditions of child training, this is a real danger is clearly shown by the results of recent experiments by French and German psychologists. In Germany, Kosog, visiting a school-room before the beginning of the lesson-hour, placed three objects, a pen-holder, a pocket-knife, and a piece of chalk, so near the edge of the teacher’s desk that they could be plainly seen by every pupil in the room. During the brief recess that followed the first lesson-hour, he removed these objects, and after the pupils had reassembled asked them what they had seen on the desk the previous hour. Hardly one of them, it turned out, had noticed the objects at all. Next day, _after leaving the desk entirely bare the first hour_, he put the same question to them at the beginning of the second hour. Now 26 per cent. of the pupils asserted that they had seen the pocket-knife, 57 per cent. the chalk, and 63 per cent. the pen-holder.