with them, and those movements of the tide wave which the ancient poet longed to comprehend
Qua vi maria alta tumescant
Obicibus ruptis rursusque in se ipsa residant.
He knows what soils are fertile, what climates genial, and (to a large extent) where mineral wealth is to be found. Moreover he knows the inhabitants of the earth, and not only the Races as they are, but the conditions which have determined the progress of each of them in the past and may affect them in the future, their natural aptitudes, their habits of industry or indolence, the features of the land wherein each dwells, and the influence of those features upon the increase or decay of population, upon the forms which industrial effort takes. Much, no doubt, still remains to be ascertained, for further discoveries in the sphere of biology may render regions healthy which have been heretofore haunted by disease, as further investigation of the forces of nature may plant industries in spots hitherto neglected. Still, broadly speaking, a point has been reached at which the conditions likely to affect the relative development of the various branches of mankind have become so far known, that students may begin to deal with them in a positive and practical way. They have passed from the chaos of conjecture into the cosmos of science.
With this incomparably fuller and more exact knowledge of the families of Man there has come a far closer and more widespread contact of those various families with one another, and in particular of the more advanced and civilized races with the more backward,
