They complained with reason. The brackish water had once been a source of health and energy to the Amphibians, but it was evident that the salt carried down into the lake by the stream had no means of escape, so that, as the water diminished by evaporation, the proportion of salt in the lake became far too great.

The children were convinced that the extreme saltness of the water was the chief cause of the torpidity of their parents and of the deterioration which they began to perceive in themselves, and this conviction caused them so much alarm, that they openly suggested emigration to one of the other lakes, which they believed to be fresh, as the only possible remedy for their ills. A few of them actually attempted the feat, but the distance to the nearest lake being great, and the Amphibians being unable to live long on land, some of them died by the way. Two or three of them gave up the toilsome journey in despair, and returned to the salt lake to report the unfortunate end of their friends. Their example was then held up as a warning to other aspiring spirits who had dreamed of fresh streams and waters new.

One or two of the emigrants, however, succeeded in reaching the nearest lake. How they fared there was not at first known to the conservative Amphibians, but during this period of uncertainty all who endeavoured to leave their old home were persecuted by their timorous companions, and those who succeeded in making their escape did so only after a prolonged and exhausting struggle. In spite of all opposition, the number of malcontents increased daily, and at last a new mode of remedying the unsatisfactory state of affairs was resorted to. The younger Amphibians in the old home seriously set to work to cut a canal from their own lake to that in which some of them believed their companions to be living happily.

The elder Amphibians, horrified at the work of destruction, continued their persecutions with renewed vigour. They refused to believe that the water of the lake was too salt; indeed, they even refused to believe that it was stagnant. They not only declared that a stream still flowed into it as of yore, but that no other stream flowed from the hills. Though ignorant of the fact that they themselves were degenerating, they were convinced that the restlessness and discontent of their children were due to a disease which should be discouraged. They urged that, even if they were to succeed in reaching the new lake, they would be unable to live in the fresh water, and that by cutting a canal between the two, they would flood the old lake, and thus diminish its saltness so considerably that the whole race would cease to thrive there.

Notwithstanding these arguments, the children persevered in their labours. The canal was finished sooner than they had anticipated, for those who had emigrated had been similarly employed, and the workers from the two lakes met in the middle of the strip of land which had formerly divided them. The results of the undertaking gave universal satisfaction. The old lake was rendered healthier by the influx of fresh water; the water of the new lake was improved by the saline flavour now imparted to it. The parents swam contentedly from one lake to the other, and saw with their own eyes the stream which flowed down from the hills and replenished the new lake.

Who could they have been, these timid, sceptical creatures, who accused their children of the want of faith which was destroying themselves?

We have seen in the above story that some of those who valiantly endeavoured to gain the new lake perished by the way, and so we find that our recent scientific advances have been a cause of nerve-trouble, apart from the persecutions they have entailed. The mental strife we have gone through in our attempt to reconcile the ideas stored in our minds, by no will of our own, with God’s ever-progressive revelation, should teach us not to instil into the minds of our children as absolute truth that which must necessarily be but approximate truth, changing always with our own development. Seeming scientific facts themselves assume a different complexion so soon as scientific discovery goes still further. Even the axiom that two straight lines continued to infinity cannot meet, ceases to be a fact to us, and is relegated to the region of rational hypothesis, when we realise that we have never so much as seen a straight line, all seeming straight lines being but parts of curves; and that the mental picture we have been accustomed to form of a straight line is but a picture of one of these curving lines. Almost the hardest thing we have to learn is the impiety of putting cherished beliefs in the place of the great God of the universe. Like Abraham, we are called upon to sacrifice our Isaac. Like Abraham, we no sooner freely consent to do so, than we find the ram ready for the sacrifice. Directly we close our eyes to God’s progressive revelation and accustom ourselves to inconsistency and to fallacious reasoning, we unconsciously deteriorate.

Another outcome of recent rapid changes has been a great increase of wealth, together with its unequal distribution. Whether this unequal distribution might have been prevented, and whether it may or may not now be remedied, cannot here be discussed. We have but to inquire whether it has anything to do with the prevalent nerve-trouble; and I think we must admit that excessive luxury on the one hand, and excessive poverty on the other, are largely productive both of monotony and overwork. At all events, it is principally amongst the well-to-do classes that ennui is complained of.

It cannot be doubted that monotony is a fertile source of nervous disease. The fact is not always received, because the nature of the evil is not understood. We fail to realise that monotony is an actual strain upon the nerves, often an even greater strain than extreme fatigue; for those who are overworked are supposed to require a holiday or change of occupation, while those who are suffering from monotony often get no relief until so much harm is done that mere change of scene or of occupation is inadequate to repair the damage done to the ill-treated nerves. In such cases the mischief wrought in the individual is similar to the mischief now being wrought in the community—in each there is excessive use of one part and disuse of another.

If we doubt that monotony is really a mode of overstrain, let us consider the very meaning of the word. Why do we speak of a preacher’s voice as monotonous, and why do we find the monotony of it tiring? Is it not because a strain is thrown upon one part? If his preaching were more varied, a number of smaller impressions would be made upon other parts. If all the light which falls upon our eyes in the course of the day were concentrated into one single flash, we should be blinded. And supposing that all the impressions we receive throughout the day by means of hearing, touching, tasting, and smelling, were to be concentrated into stimulus of the brain passing through our eyes, we should probably still be blinded, even though the process occupied the whole twelve hours. But we fondly imagine that, though we have faculties to develop and sympathies to enlarge by means of active life in the world and contact with our fellows, we can shut ourselves off from the duties and occupations which are as essential to our health as our daily food, and yet escape the deterioration and suffering which must naturally follow our over-use of one part and our disuse of another. We forget that we can never cease to receive impressions unless we actually close our senses, as when we shut our eyes and stop our ears. All we can do is to determine what set of impressions we will receive. And if we are always attracting nutriment to one particular part of our nervous system to the exclusion of others, we are going the right way to become ill-balanced. Not only are we rendering ourselves liable to mental disease by choosing bad mental surroundings, but to physical disease also, since no bodily function can be performed without the co-operation of the nervous system. Highly organised persons suffer more from monotony than others, because they have more faculties demanding healthy exercise, and also because the greater the sensitiveness of our nerve-structure, the less can we bear constant fatigue of one part.