318 SCIENCE. 
las), giving as the reason that Linnzus did not 
give the name Ursus maritimus, as usually at- 
tributed to him, and that ‘‘ the next date when 
any mention of the Polar Bear was made was 
1776, when Miller and Pallas each gave ita 
name.’’? Allow me to suggest that Mr. Rehn’s 
statement is not correct. It is true that Lin- 
neus did not give a binomial term to the Polar 
Bear, but it is not true that it did not receive 
cone until 1776. 
In 1778 Sir C. J. Phipps undertook a voyage 
to Spitzbergen, and in the account which he 
published in 1774* the Polar Bear, with full 
references to Linnzeus and Pennant and meas- 
urements from specimen, is formally named 
Ursus maritimus. I have not now at hand the 
original edition, and consequently cannot quote 
the page, but I possess the French translation 
of 1775, + in which the name occurs on p. 188. 
IT may add that Mr. Rehn’s is not the first at- 
tempt at resurrecting Pallas’s name. It was 
done as early as 1844 by Keyserling and Blasius, 
who have been followed, among others, by 
Nilsson and Pleske. But the name of the 
Polar Bear should be Thalarctos maritimus 
(Phipps). 
LEONHARD STEJNEGER. 
U.S. NATIONAL MUSEUM, 
WASHINGTON, D. C.,; August 26, 1899. 
THE MENTAL EFFECTS OF THE WEATHER. 
In reading the interesting article by Dr. 
Dexter in Scrence of August 11th under the 
above heading two or three suggestions as to 
the causes in action occurred to me and are 
perhaps worth mentioning. Dr. Dexter’s 
curves show that the greatest number of as- 
saults occur between the temperatures of 50° 
and 90° F., with amaximum between 70° and 
s0°. There isa greater number on clear and 
partly cloudy days than on days with rain. In 
other words, the conditions which we know at- 
tract people out of doors and bring them in 
contact are the conditions which, it appears, pro- 
duce the greatest number of assaults and thus, 
perhaps, are indirectly the cause of them. Even 
* Phipps (C. J.). A voyage towards the North 
Pole undertaken by H. M’s command, 1773. Lon- 
don, 1774. 4to. 
+ Voyage au Pole Boréal, fait en 1773 * * * ete. 
Paris, 1775. 4to. 
[N.S. Vou. X. No. 246. 
the slightly greater number of assaults on 
partly cloudy days than on clear days may be 
interpreted from this standpoint. The partly 
cloudy days average warmer than the clear 
days, and people are more attracted out of 
doors on mild days than on cold days. 
The number of errors in banks is found to be 
greater on cloudy and on rainy days than on 
clear days. This may be due to the greater 
amount of light on clear days by means of 
which the figures are more clearly seen. 
The number of people insured appears to be 
less on rainy days. Again, this may be ex- 
plained by a tendency of rainy days to keep 
people in doors. A man having decided to 
have his life insured on a certain day which 
proves to be rainy postpones it to a pleasant 
day, when traveling is more agreeable. 
The increased energy which people feel on 
sunny days also no doubt contributes to the 
effects described above, as suggested by Dr. 
Dexter. 
The number of deaths he found to increase 
with the temperature when the temperature 
was above 80°, and in this case there is prob- 
ably a direct relation of cause and effect. 
H. HELM CLAYTON. 
BLUE HILL METEOROLOGICAL OBSERVATORY, 
September 5, 1899. 
NOTES ON PHYSICS. 
PHOTOGRAPHY OF SOUND WAVES. 
Proressor R. W. Woop publishes in Phil. 
Mag., August, 99, some very interesting photo- 
graphs of sound waves, taken by a modification 
of the method of Toepler. A telescope objec- 
tive pointed at a star appears as a uniformly il- 
luminated field to an eye situated at or a trifle 
behind its focus, inasmuch as light enters the 
eye from every part of the objective. A con- 
densed mass of air between the lens and the 
focus turns the light which passes through it to 
one side of the focus; this deflected light may 
be cut off by means of a screen, the edge of 
which just grazes the focus, and the portion of 
the field of view which is covered by the con- 
densed mass of air appears dark. Instead of 
the eye an ordinary photographic camera may 
be focussed upon the telescope objective, and by 
using the light from an electric spark, instead of 
