Having set forth the hereditary nature of general intellectual ability, he attempts to discover what particular qualities commonly combine to form genius, and whether they also are transmissible. 'English Men of Science: Their Nature and Nurture' (1874) was a summary of the results obtained from inquiries addressed to the most eminent scientific men of England, respecting the circumstances of heredity and environment which might have been influential in directing them toward their careers. One hundred and eighty persons were questioned. From the replies it appeared that in the order of their prevalence, the chief qualities that commonly unite to form scientific genius are energy both of body and mind; good health; great independence of character; tenacity of purpose; practical business habits; and strong innate tastes for science generally, or for some branch of it. The replies indicated the hereditary character of the qualities in question, showing incidentally that in the matter of heredity the influence of the father is greater than that of the mother. It would have been interesting to have had the results of similar inquiries in the case of other classes of eminent persons,—statesmen, lawyers, poets, divines, etc. However, it is problematical whether other classes would have entered so heartily into the spirit of the inquiry, and given such full and frank replies.
Large variation in individuals from their parents is, he argues, not only not incompatible with the strict doctrine of heredity, but is a consequence of it wherever the breed is impure. Likewise, abnormal attributes of individual parents are less transmissible than the general characteristics of the family. Both these influences operate to deprive the science of heredity of the certainty of prediction in individual cases. The latter influence—i. e., the law of reversion—is made the subject of a separate inquiry in the volume entitled 'Natural Inheritance' (1889).
In 'Inquiries into the Human Faculty and its Development' (1883), he described a method of accurately measuring mental processes, such as sensation, volition, the formation of elementary judgments, and the estimation of numbers; suggested composite photography as a means of studying the physiognomy of criminal and other classes; treated the subject of heredity in crime; and discussed the mental process of visualizing.
'Finger Prints' (1892) is a study from the point of view of heredity of the patterns observed in the skin of finger-tips. These patterns are not only hereditary, but also furnish a certain means of identification—an idea improved in Mark Twain's story of 'Pudd'nhead Wilson.'
Mr. Galton is himself an example of the heredity of genius, being a grandson of Erasmus Darwin, the author of 'Zoönomia,' and a cousin of Charles Darwin. Born near Birmingham in 1822, he studied some time at Birmingham Hospital and at King's College, London, with the intention of entering the medical profession; but abandoned this design, and was graduated from Trinity College, Cambridge, in 1844. He soon after made two journeys of exploration in Africa, the latter of which is described in his 'Narrative of an Explorer in South Africa' (1853). An indirect result of these journeys was 'The Art of Travel; or Shifts and Contrivances in Wild Countries' (1855).
'Meteorographica' (1863) is noteworthy as the first attempt ever made to represent in charts on a large scale the progress of the weather, and on account of the theory of anti-cyclones which Mr. Galton advances in it.
Although strictly scientific in aim and method, Mr. Galton's writings, particularly those on heredity, appeal to all classes of readers and possess a distinct literary value. One may admire in them simplicity and purity of diction, animation of style, fertility in the construction of theory, resourcefulness in the search for proof, and a fine enthusiasm for the subject under consideration.