458 
NATURE 
[SEPTEMBER II, 1902 
shape. Modern conceptions will, we trust, give way to 
others larger and better ; in this author and reviewer are 
at one: yet their supersession will be by no such 
repentance, but by a wider and richer synthesis in which, 
no doubt, earlier and later opinions will find their recon- 
ciliation. To throw new ideas aside just to pick up 
certain old ones which, in substantially the same form, 
have prevailed and then lost their ascendancy, is what in 
the history of ideas has never happened, and, it is safe to 
say, never will happen. Secondly, to remodel our con- 
ceptions of life the thinker must not only be equipped, as 
no doubt the author is equipped, with skill in certain 
processes of research, but he must be equipped also with 
a philosophic grasp and penetration of which we see 
little evidence here. Besides the diffuse, reiterating and 
ven rambling way of dealing with the subject on which 
we have animadverted, the author has neither rigidly 
defined his terms (such as “physical,” ‘ mechanical,” 
&c.) nor repeated them even in approximately identical 
senses. Slovenly argument and confusion of language 
can only lead into the desert. 
The author deprecates rash speculation ; no specula- 
tion can be more ambitious than his, and it is none the 
less so for being elderly and familiar. The doctrines of 
the survival of the fittest may be “ingenious and fanci- 
ful,’ but his own are no less audacious and stand on 
supports at least as fragile. 
In conclusion, we must content ourselves with pointing 
out that vital phenomena depend upon causes either of 
like nature to those which are in action in heat, light, 
chemical affinity and so forth, or they depend upon some 
intrusive entity of alien origin. The author holds the 
latter opinion. We must invite those who hold this 
opinion to explain whether in their hypothesis those which 
we will call the natural forces are superseded by the 
transcendental or not? So far as our knowledge goes, 
they are converted, but neither superseded nor curtailed ; 
yet in this case how are we to conceive of them as 
entering into any sort of combination with agents with 
which they have no affinity whatsoever ? 
OUR BOOK SHELF. 
Elements of Physics. By C. Henderson, Ph.D., and 
John F. Woodhull, Ph.D. Pp.x + 388 ; with illustra- 
tions and portraits. 
Physical Experiments. By John F. Woodhull, Ph.D., and 
M. B.van Arsdale. Pp.iv + 112. (London: Hirsch- 
feld Bros., Ltd., 1902). Price 5s, net bound together. 
IT is to be feared that the former of these books (which 
are bound together) must be condemned if only for the 
astounding way in which optical images are considered. 
The image in a concave mirror is taken as being at the 
same distance behind the mirror as the object is in front, 
““because this seemed to be as reasonable as any other 
conclusion and it is a convenient measurement.” This 
rule makes the image curved, and thus its distortion is 
explained. Even the usual inverted image is placed and 
its magnitude determined in accordance with the above 
rule. Extraordinary statements such as these in the 
chapter on light make it impossible to recommend that 
the book be placed in the hands of school children, for 
whom it is intended. The other portions are not affected 
with such general misconceptions, although they are not 
‘wholly free from serious error. Thus on p. 262 it is 
NO. 1715, VOL. 66] 
| Water-Supply. 
stated that a 32 c.p. lamp requires twice the current of a 
16 c.p. lamp, and that this may be obtained either by 
doubling the voltage or halving the resistance. ‘In any 
case the heat and light will be proportional to the amount 
of current which passes.” On p. 205, in connection with 
latent heat, “Farmers understand this and put tubs of 
water in their vegetable cellars on a cold night so that if 
the temperature falls below 32° F. the freezing of the 
water will give out such quantities of heat as shall prevent 
the temperature from falling far below 32.” 
These mistakes are to be regretted the more because 
the authors appear to have striven to give, and in many 
cases have succeeded in giving, a lucid introductory 
account of the many phenomena dealt with. 
The experimental book contains a very good selection 
of experiments for school use. The discription given is 
too brief except as a general guide to the teacher. 
A. W.P. 
Types of British Plants. By C.S. Colman. Pp. xii + 
238. (London: Sands and Co., 1902.) Price 6s. 
THIS is a volume which is intended to attract and teach 
the young naturalist. It presents a short general intro- 
duction, systematic and anatomical ; it then traces out a 
developmental course, which begins with the simple 
unicellular algee, works up through the more complex 
cryptogams and finally passes in review the principal 
phanerogamic orders. In addition, a few chapters are 
given up to special features, notably trees, parasites and 
insectivorous plants. Apart from the fact that no worse 
system could be adopted than that of placing before a 
beginner a number of facts loosely strung together, this 
book has the further disadvantage of starting with the 
lower plants, which are more difficult of comprehension 
and less suited to practical examination. The descrip- 
tions, too, of the lower plants, besides being so scrappy 
as to be valueless, are couched in ridiculous language. 
Why talk of “father pits” and ‘‘mother pits ” in Fucus, 
or of a ‘‘nursery” in Vaucheria, or of “cheerful convic- 
tion” as applied to Phallus. A facetious mode of 
expression, which implies that plants possess the 
attribute of consciousness, runs through the book. 
Unfortunately, too many writers think that loose or 
facetious phraseology is necessary to make a book 
popular ; it certainly detracts from the value of any 
| scientific work. 
By Prof. William P. Mason. Third 
Edition, Rewritten. Pp. vil + 448. (New York; John 
Wiley and Sons ; London: Chapman and Hall, Ltd, 
1902.) 
THIS is the third edition of a work which has met with 
much appreciation both in this country and in America, for 
the writer is a recognised authority upon the subject with 
which he deals. Those who were familiar with the first 
two editions will note that in the present volume a con- 
siderable amount of new material has been added, and 
that the original chapters on “The Chemical and Bac- 
teriological Examination of Water” have not been 
included—for the reason that they have been separately 
published. 
There is nothing connected with water-supply—save 
engineering details of construction of water-works, &c.— 
| on which this volume may not be consulted with value. 
The writer has an intimate knowledge of his subject, 
which has been gained by a wide experience. His in- 
formation and experience is not limited to America, and 
the work is additionally acceptable to British readers 
from this circumstance—which is a somewhat exception- 
able one among American writers of works dealing with 
sanitation. 
The book is well printed and bound, and is very rick in 
excellent illustrations and diagrams. 
