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Continuously Deflecting Pyrovolter

A millivoltmeter containing Pyrovolter circuits for checking its indications on a potentiometric principle.

In this manner, the many varied and subtle disturbing sources of error involved in the resistance changes of the thermocouple (or unknown E.M.F.) circuit are eliminated.

This elimination of error, combined with simplicity of principle and operation, and sturdy construction, render the C.D. Pyrovolter a valuable instrument, where accurate electrical potentiometric measurements of small E.M.F.'s are to be made. In short-in the C.D. Pyrovolter there is the simplicity of the millivoltmeter

combined with
the accuracy of the portable potentiometer

Write us for further particulars, requesting Circular 15


TRENTON, N. J. E. F. Northrup, President and Technical Adviser

University of Colorado


Your Vacation


Field Botany, Ecology and Plant Taxonomy for students who have done work in College Botany.

The Laboratory is at Tolland, Colorado, in a mountain park, altitude 8,889 feet.

Six-week session from June 30 to August 9, 1919. An opportunity to learn much with little expenditure of time and money. For circular address the professor in charge,


The Summer Quarter 1919 will receive the added inspiration of professors and instructors returning from war service in many lands. Students and teachers, interested in keeping abreast of the times or in completing work already begun, appreciate the opportunity of instruction in a regular season of study under members of the University staff. Scholars desiring to prosecute research in the libraries and laboratories will find facilities for work under the most favorable conditions. Courses are offered in all departments and include undergraduate and graduate instruction in Arts, Literature, Science, Commerce and Administration, Law, Medicine, Education, and Divinity.


First Term June 16-July 23

Second Term July 24-August 29 Students may register for either term or both

For the complete announcement of courses address The University of Chicago, Chicago, I.



Principles, installation and use of the Mag'o Lantern, Opaque
Lantern, Projection Microscope and Moving Picture Machine;
700 pages, 400 figs. By Simon HEXRI GAGE, B.8., and
HENRT PHELPS GAGE, PH.D. Postpaid, $3.00.


Life Histories of

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of all



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nicians. In our own Laboratory

Write for List 3

Catalog B

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HOUSE 5505-5508 Kim

bark Ave., Chicago, Ill.

Catalog A




has given entire satisfaction to so many laboratories. Numerous testimonials have reached us and our prompt and efficient service invites similar expressions from our new customers.

Due to favorable connections with leading manufacturers, supported by a large stock, stored in our warehouse, we can offer prompt delivery. Our product is of foremost quality only and protected by the guarantee of our reputation.

Our staff has been trained in the scientific application of most of the apparatus and instruments; which fact assists us to make our service satisfactory.

With the aid of our mechanical and optical manufacturing departments we can attend to the construction, as well as to the repair of scientific apparatus, in accordance with the specifications of our patrons, and we know that this service has been appreciated very much by our clients.

Upon receipt of a list of your laboratory re-
quirements we will submit our estimate
promptly and we are confident that our prices
will prove interesting to you.

Catalogs and supplementary publications will be furnished upon request; in your application please refer to 0-10."

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SUGARS FOR USE IN BACTERIOLOGY DEXTROSE, Bacto, “Difcos," a carefully tested and uniform product, free from all other sugars and from starch, proteid, alcohol, and heavy metals.

Per { lb. package.

.1.25 Per lb. package.

.2.45 Per i lb. package.

.4.80 DEXTROSE, Mulford, Pure, specially prepared for bacteriological work.

Per 50 gram package. 1.25
Per 250 gram package 5.25

Per 500 gram package ..10.00 GALACTOSE, Bacto, “Difco," with low moisture and ash content, specific rotation 80.5, purity 99+%

Per 10 gram vial.

.75 Per 1 oz. package.

2.00 INULIN, Mulford, specially prepared for bacteriological work.

Per 10 gram package. 2.75

Per 100 gram package. ...25.00 LACTOSE, Bacto, “Difco," guaranteed free from Dextrose. A very fine, pure white powder, free from odor and completely soluble in water.

Per lb. package.

.68 Per lb. package.

1.30 Per i lb. package.

2.50 LACTOSE, Mulford, pure, free from Dextrose, specially prepared for bacteriological work.

Per 50 gram package.

.90 Per 250 gram package. 3.50

Per 500 gram package. 6.00 MALTOSE, Bacto, “Difco"

Per 10 gram package

.60 Per 1 oz. package.

1.60 RAFFINOSE, Bacto, “Difco"

Per 10 gram package. 1.50

Per 1 oz. package. 4.50 SACCHAROSE, C.p., Baker Analyzed

Per { lb. bottle.

.35 Per 1 lb. bottle..

1.39 SACCHAROSE, Merck white label

Per 1 oz. bottle..

.10 Per 1 lb. bottle

.24 Per 1 lb. bottle.

.75 SALICIN, for use in work on streptococci Per 1 oz. package.

2.60 XYLOSE, Bacto, “Difco"

Per 10 gram package. 10.00

Per 1 oz. package.. 25.00 Prices subject to change without notice





FRIDAY, APRIL 11, 1919



A GLANCE at the history of botany in America The Unification of American Botany: Dr. G.

shows that on several occasions special branches R. LYMAN


of the science have attained prominence, have

separated from the parent stock and taken The Elementary Course in Zoology-is it sat

independent root. These offspring are now isfactory? PROFESSOR C. E. McCluxG 345

counted as separate sciences which yield little

or no allegiance to the parent stock, and whose Wallace Clement Ware Sabine

: 47 devotees no longer call themselves botanists.

As examples we may mention bacteriology, Scientific Events:

forestry and the group of agricultural sciences The Gaspé Bird Reserves; Reorganization of represented by agronomy and horticulture-all the Farm Management Office; Corporation

subjects essentially botanical, with large and Chemistry; Memorial Professorship to Dr.

active corps of workers, but belonging to James Jackson Putnam


botany no longer.

This dissociation is undoubtedly the natural Scientific Notes and News

353 result of the growth of botany and the develop

ment of its several fields, each of which, as it University and Educational News

355 assumes a position of special importance,

develops more or less of autonomy and someDiscussion and Correspondence:

times independence. Other sciences show the Patent Reform Prospects : BERT RUSSELL.

same tendency, and I shall not attempt to Dr. Moodie's Opisthotonus: PROFESSOR

decide whether botany shows this trend toward BASHFORD DEAN. A Standard Scientific dissociation to an exceptional degree. The Alphabet: A. FANTI. Field Work in Ari- questions of immediate importance to us are: zona: F. M. PERRY

356 What are the causes of this dissociation? Are

they still operative? What new developments Quotations :

may be expected? How far can the process go Science in the British Parliament


without serious injury to botany in general?

Can the tendency be overcome in whole or in Scientific Books :

part? And if so, how? It is fitting that these Contributions to Embryology: PROFESSOR

questions should receive the serious considerFREDERIC T. LEWIS


ation of all botanists at this time for the future

is heavy with possibilities. The changes of Special Articles :

reconstruction may prove to be more fundaThe Technique of Solution Culture Experi

mental than those of war, and the responsibility ments with Plants: Dr. D. R. HOAGLAND. Unheated Egg-yolk Media: G. F. WHITE... 360

1 Invitation paper before Section G of the American Association for the Advancement of Science,

in joint session with the Botanical Society of MSS. intended for publication and books, etc., intended for

America and the American Phytopathological Soreview should be sent to The Editor of Science, Garrison-onHudson, N. Y.

ciety, Baltimore, December 26, 1918.

for American botany during this period of flux then be compared with a healthy tree surrests upon the botanists themselves.

rounded by vigorous offspring in the shape of That the tendency amongst botanists toward subsciences; rather would it be likened to an dissociation is too strong to be disregarded is ancient trunk denuded of many of its most imshown by an examination of the recent botan- portant branches which have struck root for ical programs of these winter meetings in com- themselves and are now selfishly competing parison with those of a few years ago. For- with one another and with the impoverished merly all botanists met with Section G of the parent stem. American Association for the Advancement Our problem then is to preserve the unity of of Science, and with the Botanical Society of American botany without losing the benefits of America for the reading of papers on mis- specialization. It is the old problem of concellaneous botanical subjects. Now, the plant trolling and directing the vital forces which pathologists, the geneticists and the ecologists underlie growth and development that they have independent societies; the physiologists may make for efficiency and strength rather and systematists have separate sections of the than for disunion and weakness. Botanical Society with independent programs;

I believe there is one factor more potent than and still other groups of botanists are begin- any other in promoting disunion amongst botning to request recognition and to urge that anists. That factor is not the fundamental special sessions be devoted to their subjects. scientific importance of a given field of botany, The grouping of papers according to subject nor the speed of its development. We have matter and the formation of special programs seen the rise to importance of one subject after are made necessary by the rapid increase in the another without witnessing their withdrawal number of papers presented, and doubtless are from the botanical hearthstone. It is not the desirable in every way. The formation of development of a peculiar and highly specialdifferent sections by the Botanical Society of ized technique, nor the concentration of interAmerica, and even the launching of independ- est in a particular group of plants. Neither is ent societies by various groups of botanists, are it mere number of workers in a given field, nor the natural results of rapidly mounting num- close affiliation with non-botanical subjects. bers and of increasing specialization.

All these factors contribute to dissociation There is no question but that the evolution within the ranks of botanists, but do not necof our winter programs indicates healthy essarily lead to rupture of those ranks. Pergrowth, yet we must recognize the lurking dan- haps not all combined are so potent in this ger, for we see here one evidence of the cen- respect as is economics. Whenever any branch trifugal tendency amongst botanists. Separate of botany becomes of especial economic imprograms denote and foster a concentration of portance its centrifugal tendency is enormously effort along special lines. They are one sign of increased. The general public is then interour inclination to segregate into groups, the

ested and becomes instrumental in determining special subjects in which we are interested the course of development. There is a new acting as the foci of attraction. This segrega- and greatly enlarged staff of workers, many of tion, within proper limits, undoubtedly makes whom have not received orthodox botanical for efficiency, but we must take care that it training. These workers in the new field of does not lead to undue slackening of interest in applied botany lose the isolation of the pure other botanical fields than our own, to loss of scientist, and come more closely in touch with perspective and to inability to grasp other the problems of human life. New methods of points of view. If this occurs we shall have thought appear and new standards of value crossed the danger line, ultimate estrangement arise. While the applied botanist is developing amongst botanist becomes a mere matter of the ideals of service his fellow men, he often time, and efficiency will give place to disunion over-emphasizes the importance of his own and narrowness. Botanical science could not field, loses his catholic interest in botany in

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