' Qualitative Chemical Analysis. 
908 
risks in human life without taking unnecessary 
ones.”’ 
This is very true. The analyst should ever 
stand between the public and a questionable 
supply, and the consumer, rather than the water 
purveyor, should be given the benefit of any 
doubt. 
The book closes with a consideration of the 
adulteration and examination of milk, butter, 
cereals and fermented liquors. 
The authors have had so large and varied an 
experience with the subjects upon which they 
write, that the excellence of the present contri- 
bution to sanitary literature was to have been 
expected. WILLIAM P. MAson. 
BOOKS RECEIVED. 
ALBERT B, PRESCOTT 
and Oris C. JoHNSON. New York, D. van Nostrand 
Co. 1901. Pp. xi-- 420: 
Tierleben der Tiefsee. OSWALD SEELIGER. Leipzig, 
Wilhelm, Engelmann. 1901. Pp.49. Mk. 2. 
Monographien aus der Geschichte der Chemie. Vol. V1. 
Pt. 2. Christian Friedriech Schonbein, 1799-1868. 
Grorce W. A. KAHLBAUM and ED, SCHAER. 
Leipzig, Barth. 1901. Pp. xii + 331. $9.30. 
The Induction Motor. B. A. BEHREND. New York, 
Electrical World and Engineer. 1901. Pp. 105. 
SCIENTIFIC JOURNALS AND ARTICLES. 
The Journal of Physical Chemistry, April. ‘On 
an Improved Method of determining Latent 
Heat of Evaporation and on the Latent Heat of 
Evaporation of Pyridin, Acetonitril, Benzoni- 
tril,’ by Louis Kahlenberg. Description of an 
improvement on the Berthelot apparatus for 
determining the latent heat of evaporation, in 
which the liquid is boiled by an electrically heat- 
ed platinum spiral, and the results obtained by 
itsuse. ‘A Class of Relations between Thermal 
and Dynamic Coefficients,’ by George H. Bur- 
rows. ‘Minumum Boiling-Points and Vapor 
Composition, II,’ by Morris R. Ebersole. A 
study of acetone-benzene solution, with a classi- 
fication of all mixtures of two solvents which 
have been studied, according to yapor-pressures 
and boiling points. ‘On Clapeyron’s Equa- 
tion,’ by Paul Saurel. ‘Note on the Funda- 
mental Equations of Multiple Points,’ by J. E. 
Treyor. 
SCIENCE. 
[N.S. Vou. XIII. No. 336. 
In the American Geologist for March, 8. W. 
McCauley presents a discussion on the ‘ Trap 
Dykes of Georgia.’ He states that they are all 
of the same age, and vary from an inch to two 
hundred feet in width and extend from a few 
rods to many miles. The ‘Plan of the Earth 
and its Causes,’ by J. W. Gregory, is continued 
from the February number, in which the writer 
concludes that the plan of the earth may be at- 
tributed to the unceasing shrinkage of its in- 
ternal mass. Professor E. W. Claypole contrib- 
utes some interesting notes on ‘ Petroleum in 
California.’ ‘Some Salient Features in the 
Geology of Arizona’ is discussed by William P. 
Blake. This is followed by ‘The Lake Systems of 
Southern Patagonia.’ The author of this article 
divides the lakes into three classes—residual or 
salt lakes, glacial and tectonic. The April 
number contains a valuable contribution to the 
geology of ‘The Piedmont Plateau of Georgia,’ 
by Thomas Ll. Watson. The rocks of the 
region are divided into three different kinds, 
viz., the even-grained, massive granites, the 
porphyritie granites and the granite-gneisses. 
Of the even-grained granites, all but two pos- 
sess biotite as a principal element, while 
hornblende is entirely wanting ; the porphy- 
ritic granites are, with one exception, mas- 
sive, with a composition somewhat similar to 
the massive granites, and in some places show- 
ing a gradation from one to the other ; the gran- 
ite-gneisses form extensive areas of schistose 
rock, similar in composition to the other two, 
and are believed to be metamorphosed eruptive 
granites. The author, after furnishing consid- 
erable proof, concludes that the region consists 
of eruptive granite which has been subject to 
the action of metamorphism and weathering, 
thus differentiating into the other two kinds of 
metamorphic rock. The age of the area is sup- 
posed to be Archzean, but it is crossed by numer- 
ous dykes of a later origin. Mr. Oscar H. 
Hershey contributes a paper entitled ‘ Cali- 
fornia Metamorphie Formations,’ in which he 
describes the formations of the Klamath moun- 
tain region. He concludes that the schists 
of the upper region are somewhere between 
the Archean and Deyonian in age, and favors 
the earlier rather than the later date. This is 
followed by a paper, ‘ Fossils near Montreal,’ 
