We shall find at a later stage that Malthus is keenly aware of the unhappiness caused in modern industrial societies by changes in the demand for goods, occurring even in the natural (or uninterrupted) course of trade. A movement in favour of emigration in 1806 and 1807 led him to insert a paragraph in the fourth edition of his essay which explains the relation of emigration to these changes. He accepts the statement of Adam Smith, that “the demand for men, like that for any other commodity, necessarily regulates the production of men;”[302] but he adds (as Cairnes added later) that it takes some little time to bring more labour into the market when there is demand for it, and some little time to check the supply when once it has begun to flow.[303] A family may be reared to catch high wages, and the high wages may have gone before the family has arrived at maturity. Malthus distinguishes between a normal or slight “oscillation” of this kind, and an excessive redundancy caused by an unusual stimulus to production—the stimulus, for example, of the foreign wars and the foreign trade of the years before Waterloo. In the normal case we must submit to the inevitable; in the exceptional we may find an outlet in emigration. No doubt, even if there be no emigration, in the long run the labour market will right itself; but the process will be a very painful one to the workmen concerned. Emigration is the humane and politic remedy. In some cases, such as Norway and the uplands of Switzerland,[304] there would seem to be no need for Government to teach the people to emigrate. Circumstances should do it for them; but human beings are influenced by habit and “chance” as much as by any deliberate motive, commercial or otherwise. In the Swiss uplands, as Malthus knew them, “a habit of emigration depended not only on situation but often on accident.” Three or four successful emigrations “have frequently given a spirit of enterprise to a whole village, and three or four unsuccessful ones a contrary spirit.”[305] This is illustrated by the contrast of two parishes, both in the Canton de Vaud, St. Cergues in the Jura, and Leysin[306] in the Bernese Alps near Aigle. The movements of population in Leysin puzzled M. Muret, the Swiss economist, who drew up a paper on the depopulation of Switzerland for the Economical Society of Berne in the year 1766. He found that in this parish of four hundred people there were born every year on an average only eight children, whereas, elsewhere in Canton de Vaud, to the same number of people eleven (in Lyonnais sixteen) children were a common proportion. The difference, he observed, disappeared by the age of twenty, when, if we may say so, the difference died off, the eight in Leysin being healthier than the eleven (or sixteen) elsewhere. Muret infers from this, that “in order to maintain in all places the proper equilibrium of population, God has wisely ordered things in such a manner as that the force of life in each