390 
lots should be severely punished. It seems to 
the present writer that the excrement nuisance, 
which now appears in a new and more serious 
light, cannot be got rid of until city authorities 
see their way to provide places of public con- 
venience in every ward, so that no one need 
resort to either the alleys or the saloons to obey 
the dictates ofnature. Dr. Howard has, indeed, 
provided the municipal reformer with a new 
and valuable argument, which it is to be hoped 
he will not fail to use. 
From the standpoint of scientific entomology 
Dr. Howard’s paper is of much interest. It 
records for the first time the breeding habits of 
a large number of insects, and also adds greatly 
to our knowledge of their distribution. Three 
species of flies proved to be new to science; 
these have been described by Mr. Coquillett in 
Entomological News, January, 1901. 
In all the work Dr. Howard was ably as- 
sisted by several members of his office force, 
particularly Messrs. Pratt and Coquillett. To 
these careful credit is given, in accordance with 
Dr. Howard’s invariable custom. The figures 
are numerous and clear, 25 species being illus- 
trated, often with the early stages. By some 
slip, Drosophila ampelophila is called ‘ ampelo- 
phaga’ on the plate, but the name is given 
correctly in the text. Limosina albipennis and 
L. crassimana, to judge from the figures, should 
belong to different genera. 
T. D. A. CoCKERELL. 
BOOKS RECEIVED. 
Les phénomeénes électriques et leurs applications. 
Henry Vivarnz. Paris, Georges Carré et C. 
Naud. 1901. Pp. vi+ 574. 
A Laboratory Guide in Elementary 
WitiraAm Doper Frost. Madison, Wis., pub- 
lished by the Author. 1901. Pp. viii +205. 
Ausgewahlte Methoden der analytischen Chemie. A. 
CLASSEN. Braunschweig, Friedrich Vieweg und 
Sohn. 1901. Vol. I. Pp. xx + 940. 
Essays in illustration of Astral Gravitation in Natural 
WILLIAM LEIGHTON JORDAN. New 
York and Bombay, Longmans, Green & Company. 
1900. Pp. xiv + 192. 
zeneral Report of the Investigations in Porto Rico of the 
United States Fish Commission Steamer Fish Hawk in 
1899. BARTON WARREN EVERMANN. Washing- 
ton Government Printing Office. 1900. Pp. vi+ 
350, and 50 Plates. 
Bacteriology. 
Phenomena. 
SCIENCE. 
[N.S. Von. XII. No. 323. 
SCIENTIFIC JOURNALS AND ARTICLES. 
The Journal of Physical Chemistry. December. 
‘Reaction Velocity and Equilibrium,’ by Wilder 
D. Bancroft; ‘ Differences of Potential between 
Metals and Non-aqueous Solutions of their 
Salts,’ II, by Louis Kahlenberg. A formula 
has been deduced by Nernst for the EH. M. F. 
of a galvanic chain of the type 
Ag| AgNO; (concentrated) | AgNO; (dilute) | Ag 
which shows a fair degree of agreement with 
the observed values when water is used as a 
solvent. The author has tested the formula 
experimentally in a number of cases in which 
non-aqueous solutions are used, and finds that 
Nernst’s formula does not hold good under these 
circumstances; ‘Solvent Action of Vapors,’ by 
A. T. Lincoln. A study of the solvent action 
of the vapor of water, benzene and acetone 
upon salicylic and benzoic acids, and of alcohol 
vapor upon camphor and naphthalene. 
January. ‘Gas Polarization iu Lead Accumu- 
lators,’ by C. J. Reed ; ‘ Two Devices for Circu- 
lating Liquids at a Constant Temperature,’ by 
Ira H. Derby ; ‘ On the Equilibrium of Chemical 
Systems,’ by Paul Saurel. The translation of 
the more important parts of a thesis of the same 
title, presented to the Faculté des Sciences of 
Bordeaux. 
THE first (January) number of Volume II. of 
the Transactions of the American Mathematical 
Society contains the following papers: ‘ Invari- 
ants of Systems of Linear Differential Equa- 
tions,’ by HE. J. Wilezynski; ‘ Divergent and 
Conditionally Convergent Series whose Prod- 
uct is Absolutely Convergent,’ by Florian Ca- 
jori; ‘Sets of Coincidence Points on the Non- 
Singular Cubies of a Syzygetic Sheaf,’ by M. B. 
Porter ; ‘ Note on Non-Quaternion Number Sys- 
tems,’ by W. M. Strong; ‘On the Reduction of 
the General Abelian Integral,’ by J. C. Fields; 
‘Ueber Flachen von Constanter Gauss’scher 
Krimmung,’ by David Hilbert; ‘ Note on the 
Functions of the Form f(%) =9(«) + av" + 
a,x" + --. + a, which in a given Interval differ 
the least possible from Zero,’ by H. F. Blich- 
feldt. 
THE February number of the Bulletin of the 
American Mathematical Society contains the fol- 
