246 Notices of Books. (April, 
his favourite study than by applying himself to this work when 
he returns to Europe; and we hope he may be induced thus to bring 
prominently before the scientific world a study which the present 
writer believes to be founded inductively ona wide basis of observed 
facts, and calculated to be of immense importance in elucidating 
the mental nature of man, both individually and nationally. 
In this short notice we have not been able even to allude 
to many of the interesting topics discussed by our author. His 
beautifully illustrated volume should be read by every one who 
desires to see how much valuable matter a man of genius may 
obtain during a few months’ sick leave; and how much light may 
be thrown on curious social problems, and on the early history of 
mankind, by the careful study of a few scattered families of an 
almost extinct tribe of savages. 
The Ocean: Its Tides and Currents, and their Causes. By 
WILLIAM LEIGHTON JORDAN. Longmans, Green, and Co., 
1873. 
THIS is a most vexatious book. We cannot help admiring the 
industry with which the author has studied his special subject of 
ocean currents, and to a certain degree the originality of his 
method of treating it, but in the midst of this we are thrown back | 
by the extravagance of originality and error, in the author’s 
conceptions of the fundamental properties of matter, and the 
laws of motion. His great stumbling block isthe pre-Newtonian 
idea that the vis imertie of matter is a continual striving for 
rest, or an internal resistance to the continuance of motion. He 
endows inertia with positive activity, and makes that activity all 
Se ee ees 
one sided, by representing it as an inherent property or force of © 
matter which opposes all external force sproducing motion, but — 
offers no opposition to the external forces which resist or destroy 
motion, or, to use his own words, ‘‘ I have shown that vis inertié 
opposes motion in everything, and that its own inherent property — 
of vis inertia must tend to bring a body to rest under any — 
circumstances whatever, just as much, and in the same manner, 
as the action of any force from without; and, secondly, I have | 
shown that, as regards the motions of the planets in their orbits, 
the centrifugal force which opposes the centripetal force of the 
bodies which compose the solar system one towards another, and 
all towards their common centre of gravity, is the force of astral — 
gravitation opposing that of solar gravitation; so that in their 
courses they are borne smoothly along the lines of equlibrium 
lying between opposing forces of gravitation.” 
we 
Mr. Jordan evidently imagines that the quantity of matter — 
composing the stars compensates for their distance, and thus — 
enables them to control the gravitation of the sun upon the — 
planetary members of the solar system. This utter miscon-— 
