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proportion to the number of cases taken; and they thus form the basis of what are called statistics. If I am right, it is of the very essence of statistics that each instance differs from the rest; and that the very next observation made will necessarily be different from the average already calculated. For example: if one frame, from fifty years' observations, a curve indicating the average daily tempe- rature at any given locality, it is almost certain that this year's curve will differ from the average; and it is absolutely certain that a large proportion of the daily ranges of temperature will be quite different from those calculated for corresponding days from the fifty years' observations.
This was not what Bacon meant, or what Harvey did. His aim was to establish the law by which one of the great and essential processes of life was carried on, and that this law was constant and unchangeable. IIe showed that the circulation was just as certain as the heat of summer and the cold of winter; but, in the law which he traced, there is nothing to indicate the quickness of the pulse any more than, in the changes of season, can there be found anything to determine before-hand the degree of heat or cold which may be registered by the thermometer. He saw that the blood, propelled from the heart, must return to it; he sought for the law of this phenomenon, and, having found it, was able to show that it was
