on will practice.  He believed it possible to train the will on one thing until we got it perfectly under control, and in so doing we should modify character immensely.  If this proved possible, we ought to persevere until conduct becomes an art, education a principle, and mind is known as a science is known.  Mr. Jacobs wanted systematic enquiries to be made into powers of attention, such as “Can we listen and read at the same time, and reproduce what we have read and heard.”  And into the faculties of observation and memory, with after images, and the capacity for following trains of reasoning, &c., &c., “When we read a novel, do we actually have pictures of the scenes before our minds?” Mr. Jacobs wished for enquiries into every kind of intelligence ordinary and extraordinary; out of all ingredients of character, out of early impressions, out of classified emotions to build up an answer to the question:  “Is there a science of mind?” Since he wrote, much has been done in experiment by the scientific.  Children’s minds are constantly being investigated, and the results given to the public.  Mr. Galton has to some extent popularised this sort of investigation.  But it is still generally unpopular.  Novelists, and artists, leisured people, women, everyone could be of use, if they would investigate themselves, or offer their minds for investigation.  But after all that the scientific French, German, American, Italian, and English workers have done, we are as yet only on the threshold of mind knowledge—­of what we might know—­if we had ardour enough to push self-analysis in to the remotest corner of the brain, noting down, comparing, tabulating the most involuntary and ethereal sublimities that appear to flit through the mind, the most subtle emotion that hardly finds expression in language.  We must push on and on till we arrive at the knowledge of a mind science.  Our scientific enquirers want, as we all do, more ardour, they are dulled by a cold, uninterested public.  Psychologists now seem to despair of obtaining any large results from the science.  Mr. E.W.  Scripture in “The New Psychology” says, in 1897, “It cannot dissect the mind with a scalpel, it cannot hope to find a startling principle of mental life.”  If psychological experiment could be presented somewhat apart from its technicalities, and if minds could play freely round its discoveries, how much more interesting it would be felt to be by the general public!  The great experimental worker, Mr. J. Mck Cattell has given[2] some clear idea of the results he obtained by analysing and measuring sensations.  The physical processes, which accompany sensations of sound and light for instance, unlike as they must be to sensations, being facts of matter in motion, yet share with them this characteristic, that sensations also have each an order in time, the mental processes can be measured, equally with the physical.  Of course measuring sensations is only measuring “the outside of the mind”—­but