274 
least exposure giving a good negative in the 
dark-room. This factor can certainly be treb- 
led. A plate having any intermediate expo- 
sure can be developed either as a good positive 
in the light, or as a good negative in the dark- 
room. 
It was stated that the best results with plates 
near the zero condition had been reached with 
a rather strong bath, with two drops of satu- 
rated hypo to the ounce of bath. 
Three persons were elected to active mem- 
bership. WILLIAM TRELEASE, 
Recording Secretary. 
SCIENCE CLUB OF THE UNIVERSITY OF 
WISCONSIN. 
THE January meeting of the Club was held 
on the evening of the 24th inst., President 
Birge in the chair. Professor J. M. Coulter, 
of the University of Chicago, delivered his ad- 
dress on ‘ The Teaching of Science’ (substanti- 
ally as published in this JoURNAL, Vol. XIL., p. 
281). At the close the president related an 
incident from his own early experience to show 
how completely scientific education was misun- 
derstood by the classicists, and he expressed 
the opinion that the quality of science teaching 
in the universities is not so poor as Professor 
Coulter would have us believe. The president 
extended the very evident thanks of the audi- 
ence to the speaker for his address. 
HK. R. MAURER, 
Secretary. 
DISCUSSION AND CORRESPONDENCE. 
THE SIDGWICK MEMORIAL. 
To THE EDITOR OF SCIENCE: I have been 
asked to act in America for the English com- 
mittee on a memorial to the late Professor 
Henry Sidgwick. Other Americans are prob- 
ably acting also, but of this I do not know. 
A meeting in the interests of such a me- 
morial was recently held at Cambridge, and an 
influential committee was appointed. The me- 
morial will probably take the form of an endowed 
scholarship at Cambridge, though other projects 
are also before the committee. Seeing the ser- 
vices Sidgwick rendered to education—notably 
woman’s education—and the very large use 
made of his books in American universities, it 
SCIENCE. 
[N.S. Vou. XIII. No. 320. 
is hoped that a considerable sum will be raised 
in this country. Contributions, to be forwarded 
through me, may be sent direct to Princeton, 
New Jersey. 
J, MARK BALDWIN. 
SHORTER ARTICLES. 
RADIO-ACTIVE MINERALS. 
In searching for radio-active substances with 
one of Professor Rood’s new electrometers, an 
instrument particularly well adapted to the 
purpose, several minerals not hitherto noted 
were found to be radio-active. Professor Rood 
suggested that I should try columbite, and gave 
me some specimens. The electrometer im- 
mediately shows that the air in the neighbor- 
hood of the mineral is ionized, and later pho- 
tographic tests confirm the radio-activity of 
columbite. A chemical analysis of the speci- 
mens has not yet been made, but according to 
Dana, columbite does not contain uranium or 
thorium. 
Specimens of erbium oxide and niobium 
oxide, from the museum of the chemical depart- 
ment, also show with the electrometer a slight 
ionizing effect. Further investigations are 
being made. Gro. B. PEGRAM. 
PHYSICAL LABORATORY OF COLUMBIA 
UNIVERSITY, January 26, 1901. 
THE MUSICAL BOW IN CALIFORNIA. 
In view of the present discussion in regard 
to the existence of the musical bow in America, 
and of its independent development on this 
continent, the occurrence (quite rare at present, 
however,) of a form of this instrument among 
the Maidu Indians of Northern California ap- 
pears worthy of a brief note. 
The bow as used by the Maidu is a simple 
bow of cedar, some 2} feet in length, at present 
strung with wire, but formerly with a fine sinew 
cord. In playing the instrument it is held in 
the left hand (the hand grasping the center of 
the bow, thumb inside and palm facing forward), 
the bow extending horizontally to the left. 
The right-hand end of the bow is placed in the 
open mouth, and the bow string tapped rapidly 
with a small flexible twig held in the right hand. 
By varying the size of the resonance chamber 
; (the mouth) with the aid of the tongue, and by 
opening or closing the mouth to a greater or 
