Excerpt: The following treatise includes data originally accumulated in a series of papers communicated to the Canadian Institute and the Royal Society of Canada, aiming at determining the cause of Left-handedness by a review of its history in its archaeological, philological, and physiological aspects. In revising the materials thus accumulated in illustration of the subject, with a view to their publication in a connected form, the results of later investigation have been embodied here, not only with the aim of tracing Left-handedness to its true source, and thereby proving the folly of persistently striving to suppress an innate faculty of exceptional aptitude, but also to enforce the advantages to be derived by all from a systematic cultivation of dexterity in both hands.