Page:Popular Science Monthly Volume 29.djvu/44

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HE first edition of Alphonse de Candolle's "History of the Sciences and of Scientific Men during two Centuries," which was published in 1873, was speedily exhausted, and the book became, as the author says, a rarity in the library catalogues. A search for it two years ago revealed the fact that there was but one copy to be found in the European markets, and that was held at three times the ordinary price. Frequent references to the work as an authority, and many inquiries for it, made a second edition necessary, and it has appeared, with careful revisions and valuable additions, within the year. The primary object of the work was to study the influence of heredity in developing men of science; but it was obvious from the outset that this was only one of many factors that concurred in producing the result, and by no means always a predominant one. Hence the task became at once that of learning what influence was contributed by birth, and what by exterior circumstances, such as education, examples, institutions, etc. The mixture of the two categories is often inextricable, as Mr. Galton has remarked, but in many cases we may succeed in determining which one of them is predominant.

M. de Candolle precedes his principal study with general discussions of the subjects of heredity and selection, and of the operation of selection in the human species, to which he has added in the later edition of his book an account of his processes and the results of his newer investigations on heredity. The latter were made upon thirty-one persons belonging to sixteen different families in comfortable circumstances, and bore reference to 1,032 distinct traits of character, for each of which he also inquired into its presence or absence in either or both parents. These traits were arranged in four categories: external, 287; internal, 140; instinctive and sentimental, 410; and intellectual, 195. The general result of the examination was to show in a striking manner that heredity is the usual, general, and predominant law, in both sexes and various degrees for all the categories of characteristics not acquired. Other facts of more limited application were brought out. Interruption of heredity during one or more generations, or atavism, was rarely presented, and seemed to say, when it occurred, not that the particular trait was wanting, but that it was feebly accentuated, in the intermediate generations. The more prominent or influential the