SCIENCE—ADVERTISEMENTS 
Marine Biological Laboratory 
Woods Hole, Mass. 
Facilities for reseach in Zoology, 
Embryology, Physiology and Bot- 
any. Seventy-six private labora- 
tories, $100 each for not over three 
months. Thirty tables are avail- 
able for beginnersi n research who 
desire to work under the direction 
of members of the staff. The fee 
for such a table is $50.00. 
INVESTIGATION 
Entire Year 
Courses: of laboratory instiuction 
with lectures are offeredin Inverte- 
brate Zoology, Embryology, Physi- 
ology and Morphology and Taxo- 
nomy of the Algae. Each course 
requires the full time of the student. 
Fee, $50. Alecture course on the 
Philosophical Aspects of Biology 
and Allied Sciences is also offered. 
INSTRUCTION 
July 3 to August 13, 
1918 
Animals and plants, preserved, liv- 
ing, andinembryonicstages. Pre- 
served material of all types of 
animals and of Algae, Fungi, Liver- 
worts and Mosses furnished_for 
classwork, or for the museum. Liv- 
ing material furnished in season 
as ordered. Price lists of Zoological 
and Botanical materia ]sent on ap- 
lication. State which is desired. 
or price lists and all information 
regarding material, address 
GEO. M. GRAY, Curator, Woods Hole, Mass. 
The annua) announcement willbe sent on application to The 
Director, Marine Biological Laboratory, Woods Hole, Mass. 
SUPPLY 
DEPARTMENT 
Open the Entire Year 
The L. & N. 
High Sensitivity Galvanometer 
An instrument 
of extremely 
high sensitivity, 
yet one with 
whichitisa 
leasure to work 
ecause it is very 
easily set up and. 
its working char- 
acteristics are all 
that could be de- 
. sired. 
If you have 
any research 
work involving 
the use of a gal- 
vanometer of high sensitivity this instrument 
can be built to your order, giving you the 
maximum sensitivity under your working con- 
ditions. 
We solicit correspondence from those who are look- 
ing for an out-of-the-ordinary galvanometer 
THE LEEDS & NORTHRUP CO. 
4921 Stenton Avenue PHILADELPHIA 
Memoirs of the Wistar Institute of Anatomy and 
Biology. No. 6, 1915 
THE RAT 
Data and Reference Tables. 278 Pages. 89 Tables. 
_Bibliozraphy. 
Compiled and Edited by HENRY H. DONALDSON. 
Postpaid $3.00. 
The Wistar Institute Philadelphia, Pa. 
The Microscope 
12th Edition, Published April 10, 1917 
Re-Written and largely Re-Illustrated 
By SIMON HENRY GAGE of Cornell University 
Postpaid $3.00 
COMSTOCK PUBLISHING CO., Ithaca, N. Y. 
The New Science of the Fundamental Physics 
By W. W. STRONG, Ph.D. 
Includes chapters on the Goal of the New Physics, 
the Directed Elements, the Atomic Systems and 
Models, Disintegration and Radiation Theories, 
Elementarquanta, the Fundamental Units and Rel- 
ativity. 117 p. cloth. $1.25. 
S. I.E. M. CO., Mechanicsburg, Pa. 
Teachers Wanted 
We have a steady demand for men in all depart- 
ments of Science for Agricultural Colleges, and Uni- 
versities. Special terms. Address 
The Interstate Teachers’ Agency 
Macheca Bidg. New Orleans, La. 
“ Detroit ” Laboratory Burner 
The Standard Burner for Laboratory uses of every char- 
acter—most economical to operate. A 
It produces a stiff, blue flame of maximum temperature, 
with use of Air Blast. 
Separate control of both air andgas. Will not flash back, 
clog or sing. 5 
Guaranteed to work on any kind of gas—city coal gas, 
natural or gasoline-gas. 
In your next order specify the ‘‘ DETROIT” and get the 
best. The name “DETROIT” is stamped on the burner— 
look out for imitations. Ask us for name of dealer in your 
vicinity, or order direct. 
Prices: Less than doz. lots, $1.25 each; Lots of 1 doz. 10 per 
cent. discount; Lots of 12 doz. 20 per cent. discount. 
DETROIT HEATING & LIGHTING 
COMPANY 
632 Wight Street Established 5868 DETROIT, MICH. 
