The traveller must not generalize on the spot, however true may be his apprehension--however firm his grasp, of one or more facts. A raw English traveller in China was entertained by a host who was intoxicated, and a hostess who was red-haired; he immediately made a note of the fact that all the men in China were drunkards, and all the women red-haired. A raw Chinese traveller in England was landed by a Thames waterman who had a wooden leg. The stranger saw that the wooden leg was used to stand in the water with, while the other was high and dry. The apparent economy of the fact struck the Chinese; he saw in it strong evidence of design, and wrote home that in England one-legged men are kept for watermen, to the saving of all injury to health, shoe, and stocking, from standing in the river. These anecdotes exhibit but a slight exaggeration of the generalizing tendencies of many modern travellers. They are not so much worse than some recent tourists' tales, as they are better than the old narratives of "men whose heads do grow beneath their shoulders." Natural philosophers do not dream of generalizing with any such speed as that used by the observers of men; yet they might do it with more safety, at the risk of an incalculably smaller mischief. The geologist and the chemist make a large collection of particular appearances, before they commit themselves to propound a principle drawn from them, though their subject matter is far less diversified than the human subject, and nothing of so much importance as human emotions,--love and dislike, reverence and contempt, depends upon their judgment. If a student in natural philosophy is in too great haste to classify and interpret, he misleads, for a while, his fellow-students (not a very large class); he vitiates the observations of a few successors; his error is discovered and exposed; he is mortified, and his too docile followers are ridiculed, and there is an end; but if a traveller gives any quality which he may have observed in a few individuals as a characteristic of a nation, the evil is not speedily or easily remediable. Abject thinkers, passive readers, adopt his words; parents repeat them to their children; and townspeople spread the judgment into the villages and hamlets--the strongholds of prejudice; future travellers see according to the prepossessions given them, and add their testimony to the error, till it becomes the work of a century to reverse a hasty generalization. It was a great mistake of a geologist to assign a wrong level to the Caspian Sea; and it is vexatious that much time and energy should have been devoted to account for an appearance which, after all, does not exist. It is provoking to geologists that they should have wasted a great deal of ingenuity in finding reasons for these waters being at a different level from what it is now found that they have; but the evil is over; the "pish!" and the "pshaw!" are said;