744 
It is in the instructor’s manual, likewise, 
that the spirit of the author’s laboratory meth- 
ods comes more clearly to the foreground. The 
presentation is more intimate, the descriptions 
more comprehensive, and the insight into the 
training which the course is intended to give 
more manifest. The genial set of instructions 
headed ‘How to Fail in Laboratory Work,’ 
might serve a good purpose if prominently 
exhibited in the laboratory. But the main 
point to be noted is the thorough apprecia- 
tion of the fact that the psychological experi- 
ment carries with it its own conditions and 
peculiarities; that in becoming a ‘subject’ 
the individual retains all his peculiarities ; 
and that these must be dealt with by tact and 
resource. The difference between good and 
bad observation upon mental matters depends 
upon this, almost equally with the acquaintance 
with method and technique. Both for the 
method and the matter, these volumes and the 
two to follow must be valued as amongst the 
most important of recent contributions to the 
furtherance of the aims of experimental psy- 
chology. JOSEPH JASTROW. 
Peach Leaf Curl: Its Nature and Treatment. By 
NEWTON B. PIERCE, in charge Pacific Coast 
Laboratory, Santa Anna, California. Bulle- 
tin No. 20, Division of Vegetable Physiology 
and Pathology, U. 8. Department of Agri- 
culture. Washington, Government Printing 
Office. 1900. Pages 1-204; plates I.-XXX. 
A carefully detailed and exhaustive account 
of the geographical distribution, history, horti- 
culture, botany and pathology of this destruc- 
tive disease, and of experiments with the 
various remedies, methods and appliances for 
treating it. The most important of the con- 
clusions is that very large percentages of the 
injuries due to the parasitic fungus Exoascus 
deformans are not caused by the renewed growth 
of perennial mycelium, but are the result of 
new infections occurring in early spring, and 
thus preventable by spraying the still unopened 
buds with Bordeaux mixture or other fungi- 
cides. Previous failures with such treatments 
are explained by the fact that the remedy was 
applied after the pathogenic organism had 
hidden itself in the tissues of its host. 
SCIENCE. 
(N.S. Vou. XIII. No. 332. 
As the annual losses from leaf curl in the 
United States are estimated at $3,000,000, the 
determination of these simple points is of great 
economic importance, and also of the widest 
interest, since this disease, unlike the yellows, 
extends to all regions where the peach is culti- 
vated. & ; 
BOOKS RECEIVED. sae 
Select Methods of Food Analysis. HmENRY LEFFMANN “’ 
and WILLIAM BEAM. Philadelphia, P. Blakis- 
ton’s Son & Co. 1901. Pp. viii + 383. $2.50. 
Levolution du pigment. G. BoHN. Paris, G. Carré 
and C. Naud. 1901. Pp. 96. 2 fr. 
Towers and Tanks for Water Works. J. N. HAZLE- 
HURST. New York, John Wiley & Sons; London, 
Chapman & Hall. 1901. Pp. ix + 126. 
SOCIETIES AND ACADEMIES. 
AMERICAN MATHEMATICAL SOCIETY. 
A REGULAR meeting of the American Mathe- 
matical Society was held at Columbia Univer- 
sity, New York City, on Saturday, April 27, 
1901. About thirty-five persons attended the 
two sessions. Vice-President Thomas 8. Fiske 
occupied the chair. The following persons 
were elected to membership: Mr. C. W. McG. 
Black, Yale University; Dr. S. E. Slocum, 
University of Cincinnati. Two applications for 
membership were received. 
To relieve the increasing burden of adminis- 
tration, the office of Assistant Secretary was 
created and filled by the appointment of Dr. 
Edward Kasner, to serve until February, 1902. 
The library of the Society, which at present 
consists mainly of some five hundred unbound 
volumes of journals received as exchanges, is 
about to be deposited in the library of Columbia 
University, under an agreement by which the 
University undertakes to bind, catalogue and 
care for the books now on hand and all future 
additions, and to make them easily accessible to 
the members of the Society. Arrangements 
will be made by which the books may be tem 
porarily loaned to members living at a distance. 
The library is to be kept as a separate collec- 
tion, duplicating as far as may be the general 
University library, and aiming to become as 
complete as possible in itself. The title to the 
books remains in the Society, which reserves 
