<P>Originally published in 1926, the first part of this book attempted to formulate a theory of ability in the light of recent experimental results of the time. It discusses the nature of intelligence and the problem of special abilities, and includes a study of some typical forms of genius. The second part gives an account of a three years' experimental study of special abilities in arts and science respectively, carried out upon university students. Samples of the tests employed are included. The results are presented in non-technical form. Victoria Hazlitt was a pioneer of experimental psychology, which was particularly significant as a woman in the early twentieth century. In many cases her work anticipated later developments in psychology by many years. Today it can be enjoyed in its historical context.</P>