MAarcH 31, 1904] 
NA LORE 
loss of whose cooperation the editor has to deplore are 
Prof. Herdman and Mr. W. A. Brown. 
In these circumstances, we have to offer special 
congratulations to Dr. Sharp on the appearance of this 
volume. We may at the same time take the oppor- 
tunity of mentioning our satisfaction at the decision 
of the council of the Zoological Society to continue, at 
all events for the present, the publication of this in- 
valuable record. Without in any way disparaging the 
““ International Catalogue of Scientific Literature,’’ it 
is quite certain that, in present circumstances, the 
zoological portion could not be issued with that prompt- 
ness which renders the ‘‘ Record ”’ before us so invalu- 
able to working naturalists. 
Since all the contributors are specialists, thoroughly 
acquainted with their respective subjects, there is little 
or nothing to criticise in the technique of their work, 
and the present volume seems remarkably free from 
typographical errors. As usual, some of the recorders 
treat their subject, both in the way of introduction and 
in the class of papers quoted, at much greater length 
than others. In some sections—the mammals, for ex- 
ample—it appears to be the recorder’s custom to 
exclude papers which do not contain absolutely new 
matter, and also those in which there is merely more 
or less incidental allusion to the particular subject, or 
summaries of previous work. In other sections— 
like the one on echinoderms—precisely the opposite 
course is followed, papers containing even the most 
remote and unimportant references to the subject being 
catalogued. Consequently, some of the pages in the 
section last cited look more like a geological than a 
zcological record. 
It is not, of course, for us to decide which course is 
preferable. If, however, the more comprehensive plan 
is necessary in one section, it is apparently required in 
all, and vice versd. The universal adoption of the 
fuller plan would largely increase the bulk of the 
annual volume, while if the system of elimination were 
followed throughout, its size would be proportionately 
reduced. 
As an instance of our meaning, we may note that 
some writers quote the articles on their respective sub- 
jects from the volumes of the ‘‘ Victoria County 
History,’’ while by others they are omitted. Again, 
in one section (Echinoderms) we find the ‘‘ Guide to 
the Dublin Museum”’ entered, which is surely un- 
necessary. In the same record also occurs Prof. 
Sollas’s paper on the method of investigating the struc- 
ture of fossil animals by means of sections, a paper 
which should have appeared only in ‘‘ General Sub- 
jects,’’? where it is conspicuous by its absence. 
How absolutely essential to zoological workers—if 
they are to avoid using preoccupied names—is the 
prompt appearance of the ‘‘ Record ’’ may be inferred 
from the long list of new generic and subgeneric terms 
at the end of the present volume, which runs to 18 
pages, against 16 in its predecessor. 
In conclusion, we may direct attention to the request 
that authors would send copies of their papers to the 
editor. Labour would thus be saved to the recorders, 
and the prompt insertion of papers would be secured. 
R. L. 
NO. 1796, VOL. 69] 
| Law ’’ (of gravitation) ‘Sis not a simple law. 
| cut in two. 
OUR BOOK SHELF. 
4ither and Gravitation. By W. G. Hooper. Pp. 
xiv+358. (London: Chapman and Hall, Ltd., 
1903.) Price 12s. 6d. net. 
From a psychological point of view this treatise of 358 
pages is very interesting. The author “has en- 
deavoured to perfect a theory which will bring ztherial 
physics more into harmony with modern observation 
and experiments.’? He ‘“‘has taken Newton’s Rules 
of Philosophy as his: guide in the making of the new 
theory, as he believes that if any man knew anything 
of the Rules of Philosophy, that man was Sir Isaac 
Newton.”’ 
These rules are :— 
(1) ‘Simplicity of conception.’’ ‘If there are 
apparently two causes to the same phenomenon, then 
the simpler cause is the true and correct one.”’ 
(2) ‘‘ Agreement with experience, &c.”’ 
(3) ‘‘ Satisfactorily accounting for and explaining all 
phenomena sought to be explained.” 
These rules are first applied to gravitation. ‘* The 
It is 
compounded primarily of three parts. Ist, a primitive 
impulse; 2nd, a centripetal force; 3rd, a centrifugal 
force. To these must be added the three laws of 
motion.”’ 
No known medium has been found to be absolutely 
frictionless. ‘‘ Accepting therefore experience as a 
guide we are compelled to come to the conclusion that 
there is no such thing in the Universe as a frictionless 
medium. Such a hypothesis is contrary to all laws 
and rules of Philosophy,’’ ‘“‘ and therefore as either ex- 
perience or a frictionless medium has to go, we will 
part with the frictionless medium.’’ ‘‘ With the pre- 
sent conception of a frictionless zther, however, it is 
philosophically impossible for the azther to exert force 
on any body that may exist in it. Because to the ex- 
tent that it is frictionless, to that extent it ceases to 
possess mass. If it does possess mass, then it cannot 
be frictionless. ”’ 
The next point dealt with is matter, which is thus 
defined :—‘‘ Matter is that which can be perceived by 
the senses, or is that which can be acted upon by 
motion, or which can exert motion.”’ 
Incidentally we learn that vortex atoms cannot be 
“Tt will be found that when the knife is 
brought near te them they seem to recoil from the 
knife.’ 
Chapter iv. is entitled ‘‘ 4Zther is Matter.’’ In this 
chapter we learn something of the constitution of 
atoms. 
‘“Tf therefore it holds good in Philosophy that the 
small things are the index to the greater, then the con- 
verse holds good, that what is true of the large is true 
of the small, and that the laws governing the great 
also govern the small.’’ ‘‘ So that gathering up those 
chief properties of the earth to which I have already 
referred, and applying them to an ztherial atom, or 
any other atom if necessary, we arrive at the con- 
clusion that an atom must be spherical in shape, must 
possess rotation, and must have an orbit, must possess 
polarity, and also be subject to the universal Law of 
Gravitation.”’ ‘‘ Further, if we are to be strictly 
correct, in our analogy between the earth and the 
ztherial atom, its polar diameter must be shorter than 
its equatorial diameter, as that is one of the facts 
observable regarding the shape of our earth.” 
Similar lines of argument are applied in succeeding 
chapters to heat, light, electricity, and the universe in 
general. The author has read many books. He has. 
not always succeeded in understanding them. 
W. M. H: 
