or their descendants across an interval of four or five generations.
Now the particular modes and departments of linguistic change are so diverse that no one cause, or kind of causes, can affect them all, or affect them all alike, either to quicken or to retard them. But the plainest and most apprehensible influence is that which is exerted by change of external circumstances, surroundings, mode of life, mental and physical activity, customs and habits; and to this, accordingly, we will first direct our attention. How powerfully such causes may act upon language will be best shown, perhaps, by imagining an extreme case. Suppose an illiterate English family to be cast away upon a coral islet in the Pacific, and to be left there isolated through a succession of generations. How much of our language would at once begin to become useless to them! All that is connected with variety of scenery, as hill and dale, as rock and river; with diversity of season, of temperature, of skyey influences; with wealth of animal and vegetable life; with multifariousness of experience, of occupation, of material, of production—and much more, which it is needless to specify. For a certain period, some part of this might be kept alive by memory and tradition, but not for ever; it would lose its distinctness before the mind, become shadowy, and by degrees die out; and its loss would be facilitated by that stupefying effect which the climate and mode of life, with their restricted limits and dull uniformity, would unavoidably have upon the mind; vigour of thought and liveliness of sentiment would be likely to decline; and, after the lapse of a sufficient period to allow these causes their full effect, the wealth of English speech might be reduced to a poverty comparable with that of some among the present Polynesian dialects. But suppose, on the other hand, a Polynesian family set down in the midst of a country like Iceland, amid magnificent and terrible scenery, amid varieties of nature innumerable, where hard labour and prudent forethought, tasking all the moral and physical energies of man, are needed to preserve life and make it endurable—suppose them to be able to bear and adapt themselves to this tremendous change, and how rapidly would
