2 NATURE 
The remarkable fact is brought to notice that the term 
sky-blue is almost unknown in the ancient writings of any 
Asiatic people, e.g. in the Vedic hymns, in the Zend- 
Avesta, in the Old Testament, in Hebrew writings gener- 
ally, and in Homer and Hesiod ; the epithets applied to 
the sky being expressive of its vastness, depth, purity, 
brilliancy, &c., but not of its colour. A similar want of a 
precise colour-term is shown to exist in many modern 
barbarous languages. 
to conclude that sky-blue was a colour unknown to these 
peoples ; indeed sky-blue pigments have been found 
(p. 37) at both Memphis and Thebes. 
A part of Dr. Magnus’s theory of the evolution of the 
colour-sense is that the eye acquired the power of recog- 
nising different colours in the order of their luminosity ; 
but the order which he seems to assign (p. 71), viz. red, 
yellow, &c., is certainly not that of their luminosity. 
The physiological and emotional effects of colours on 
men and animals are noticed in this connection. Thus 
red is known to excite bulls and turkeys : the experiments 
of M. Paul Bert on the small crustacean Daphnia are 
quoted ; when placed in a solar spectrum they congregate 
most thickly in the orange to green region, which is also 
the most luminous region. Goethe’s speculations on the 
effects of colour on the emotions of mankind are noticed 
at length. A curious “ colour-treatment ” (chromo-photo- 
thérapie) proposed for the insane is also mentioned, which 
consists in placing the patients amidst surroundings of a 
tint supposed to be capable of exciting healthful effects : 
thus red is said to excite, blue and violet to sadden, green 
to soothe. The results of this treatment do not seem to 
have been very definite (pp. 78, 79). 
The comparative philology of colour-terms takes up— 
But it does not seem warrantable | 
as might be expected-—much of the work; the author has | 
spared no pains in endeavouring to trace out the mean- 
ings of Homer’s colour-terms by the help of the related 
words in other languages. As to the uncertainties of this 
process, take the words related to d/ve as an instance. 
Mr. L. Geiger’s opinion is quoted (p. 50) that the modern 
European words élwe, blae, blau, bid, bleu, &c. (English, 
Scotch, German, Danish, French), now meaning Jd/ue, 
meant dack in early Europe, whilst another (p. ror) 
connects them with words conveying the idea of bright- 
ness, ¢.g. b77ller, blanc, blink, bleach, blank. 
The author promises a further instalment of this essay, 
in which the evidence from the fine arts, pottery, and 
dyers’ work, and that from morphology and physiology are 
to be set forth ; also a full statement of conclusions. 
ALLAN CUNNINGHAM (Major, R.E.) 
OUR BOOK SHELF 
The Fournal of the Engineering Society of the Lehigh 
University, March, 1886.) 
THE practice of forming engineering societies in universi- 
ties where engineering is taught is an exceedingly good 
one, and should receive every encouragement and help 
from the authorities. In fact every college should have 
its society. The meetings give the students an oppor- 
tunity of discussing interesting engineering works, and 
give them a greater interest in the subject-matter taught 
in the class-room. These junior engineering societies, if 
I may so call them, ought not to be only found in col- 
leges, but all large engineering works should have a 
| May 6, 1886 
society of their own, the members of which should in- 
clude those of the pupils, apprentices, and men who are 
anxious to improve themselves by the reading and dis- 
cussing of papers prepared in rotation by the members 
themselves. Visits to other works might also be arranged. 
No doubt the formation of such societies may seem very 
hard to accomplish, but in most works there will be found 
men willing and anxious to form such societies and to 
keep them going until their utility is recognised. 
The Yournal before us contains several articles of an 
interesting nature, the first being by Prof. Merriman on 
“The Internal Work and the Deflection of Beams” ; the 
second article gives an account of “Boring the Big 
Aqueduct” for the New York water-supply from Croton 
Lake. We next have a short notice on technical educa- 
tion in Mexico, followed by a very good account dealing 
with ‘“‘ The Requisites of a Successful Engineer.’ 
After notices on “ Mine Water Formations” and “ The 
Foundations of the Washington Monument,” the Fournal 
concludes with a condensed report dealing with the 
measurements necessary to ascertain “the velocity and 
discharge of the Lehigh River about Bethlehem.” 
Taken as a whole the contents of this Foal are dis- 
appointing from a professional point of view, Prof. 
Merriman’s article on the deflection of beams being 
excepted. The descriptions are much too general and 
popular ; the subjects are not treated with that accuracy 
demanded by an engineering article, and are written in a 
style more fitted for the columns of a daily paper than a 
journal published by an engineering society. 
Neue 
Fresentus’s Quantitative Analysis, Parts I.and II. Vol. II 
Translated by C. E. Groves, F.R.S. From New Edition 
of Fresenius commencing in 1877. (No date.) 
IT is a great pity these books cannot be pushed forward 
muchfaster. The plan adopted by many German authors of 
sending out books in “Lieferungen ” has some advantages, 
but generally these are more than balanced by the time 
allowed to elapse between each part. This slowness on 
the part of authors makes it somewhat unpleasant for a 
translator, who must of necessity be still somewhat later. 
In this particular instance, however, the translator has 
improved on the time by introducing or referring to 
methods not in the original, but it might have been 
carried further. The original does not contain anything 
about Victor Meyer’s methods of vapour-density deter- 
mination, and the translator has also refrained from 
noticing these methods. 
this, but we think at least the methods might have been 
mentioned, as they are simpler to perform than any other, 
and do not fall behind any in accuracy. 
The whole of Part I. and a small portion of Part II. is 
taken up with analysis of organic bodies ; the remainder 
of Part II.is on the analysis of potable and spring waters, 
&c. If an index or table of contents had been added, it 
would have rendered the English edition more practical. 
LE LEDERS LOVLAE PE DPIROR: 
{Zhe Editor does not hold himself responsible for opinions ex- 
pressed by his correspondents. Neither can he undertake to 
return, or to correspond with the writers of, rejected manu- 
scripts. No notice is taken of anonymous communications. 
[The Editor urgently requests correspondents to keep their letters 
as short as possible. The pressure on his space ts so great 
that it ts impossible otherwise to insure the appearance even 
of communications containing interesting and novel facts.| 
Protective Influence of Black Colour from Light and 
Heat 
In NaTuRE, vol. xxxiii. p. 559, a correspondent refers to the 
effect of blackening the skin round the eyes as a protection 
against the glare of strong sunlight. Probably the practice has 
good scientific grounds. 
There may be some reason for 
