662 
Technical schools should make every en- 
deavor to develop men who are capable of 
advancing the art and who are not mere fol- 
lowers of “best practise,” an end that may be 
secured by the more general use of books of 
this type. The reviewer agrees thoroughly 
with the author’s point of view and in general 
with his methods; minor criticisms seem un- 
necessary. The lack of reference to the work 
of others is noticed. The abbreviation of 
“logarithm” to In, in the same font as is 
used for expressing quantities, seems unde- 
sirable; thus, Im z is not recognized at once as 
the familiar log 7 Some statements in re- 
gard to units might well be qualified by the 
insertion of “sometimes used” or of some 
similar phrase; since, for example, no elec- 
trical congress has recommended the “ gil- 
bert ” or the “ abvolt,” objection may be taken 
to the statements that the O.G.S. unit of mag- 
netic potential difference zs the “ gilbert” (p. 
92) and the C.G.S. unit of electric potential 
difference zs the “abvolt.” In general, how- 
ever, the phraseology is precise. 
FREDERICK BEDELL 
Flectro-Analysis. By Epcar F. Smit, Pro- 
fessor of Chemisty and Provost, University 
of Pennsylvania. Fifth edition. Philadel- 
phia, P. Blakiston’s Son & Co. 1911. 12mo. 
332 pages, 46 illustrations, flexible leather 
binding. Price ? 
The revised and enlarged edition of this at- 
tractive and useful book contains, as new ma- 
terial, the essentials of all that has appeared 
upon electro-analysis during the past four 
years. The author particularly emphasizes his 
continued success in using the mercury cup 
and his conviction of its wide utility in elec- 
trolytie analysis. To those unfamiliar with 
the previous editions it may be said that the 
work contains practically everything of value 
extant in electro-analysis, presented in most 
attractive and available form, and that pos- 
sibly half of the whole subject matter is the 
direct work of Dr. Smith and his students and 
assistants. It is quite pertinent to call atten- 
tion to the fact that many of the methods of 
SCIENCE 
[N.S. Vou. XXXV. No. 904 
exact quantitative separation and precipita- 
tion used in electro-analysis are borrowed from 
and constitute modifications of industrially 
applied processes; this is especially true of 
the mercury cathode methods; reciprocally it 
is even still more evident that many valuable 
industrial processes have evolved from the 
laboratory investigations and the exact ma- 
nipulations of electro-analysis, and yet more 
are waiting to be developed. This reciprocal 
excitation of laboratory and works is a par- 
ticularly gratifying object lesson in modern 
scientific and industrial interdependence. 
We therefore recommend the book most heart- 
ily, not only to chemical analysts, but just as 
strongly to technical electrochemists studying 
the problems of electrochemistry, both in the 
research laboratory and in the works. 
JosEpH W. RicHarps 
THE HABITS OF FLIES OF THE GENUS 
CORDYLOBIA, PARASITIC ON MAN 
IN AFRICA 
In Africa the larvee of certain flies (Cordy- 
lobia) of the family Muscide are parasitic 
under the skin of man and other warm-blooded 
animals in the same manner as are the larve 
of many of the flies usually grouped together 
as (stride. Until recently the manner in 
which Cordylobia infected its host was un- 
known. Independent results have now thrown 
light on this question. 
Monsieur E. Roubaud, in the Comptes Ren- 
dus Hebdomadaires des Séances de VAcade- 
mie des Sciences of the 23d of October, 1911. 
presents the results of his studies of the “ Ver 
du Cayor,” Cordylobia anthropophaga Blan- 
chard. The larva is found under the skin of 
man and domestic animals. In the Cstride, 
with the forms found in tumors under the 
skin, two distinct modes of infection of the 
host are known. In both cases the eggs of the 
fly are laid upon the host. In one case the 
newly hatched larve penetrate at once to their 
proper habitat, but in the other the eggs are 
swallowed by the host and the newly hatched 
larve bury themselves in the tissues of the 
cesophagus and only reach the surface after 
protracted wanderings within the body of 
