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This burette, while sacrificing none of the accuracy possessed by the Hempel, Orsat or McIntosh-Elliott, very greatly decreases the time necessary for an analysis. A complete analysis of coal, water, natural fuel, producer, acetylene, or gasoline gas, comprising determinations of any or all of the following constituents: carbon dioxide, illuminants, oxygen, carbon-monoxide, methane, hydrogen and nitrogen, can be made in from twenty to twenty-five minutes. The saving in time is effected by the elimination of the necessity of shifting the gas from one portion of the apparatus to another. With each outfit we send a 20-page treatise by Mr. Morehead on “ Industrial Gases," giving full directions for using the apparatus.
Furnished complete with Support, Aspirator Bottles and Rubber Tubing, as illustrated. Also furnished complete as illustrated, but the Burette supplied with Water Jacket for securing constant temperature.
Further information and prices on application.
E. H. SARGENT & CO.
155-165 EAST SUPERIOR STREET
CADMIUM STANDARD CELLS
For use with potentiometers, electrometers, aad ballistic galvenometers, or wherever else a precision standard of electromotive force lo needed.
Negligible Temperature Coeficient.
Highly Constant E, M, F.
Mounted in moulded box, or unmounted.
On November 13, 1916, three normal cadmium cells made by me
their group of reference cells by less than one part in one hundred thousand, 21 three having the same value.
On March 30 1930. after the lapse of three years and four months the same three cells were again compared by the Bureau of Standards. The maximum difference among the three was less than one part per hundred thousand, and the maximum difference from their oertibed value of 1916, was less than one part per bundred thousand.
In other words, these cells showed a degree of constancy to all intents equal to that considered most bighly satisfactory, if not remark. able, in the very best type of precision resistance standarde (See Bul. Bur. of Stand. Vol. 5, No. 3, D. 427.)
The cells in question were in nowise special. They were made of the materials regularly prepared by me, and were set up with no greater are than that constantly employed in the maklag of my stan. dards.
NEWPORT, R. I.
No Laboratory Equipment is complete without some variable resistances. To maintain the high standard of your outfit wo suggest the addition of some
"Becbro" Sliding Contact Rheostats
(Tubular and Stone Types)
Thousands of these rheostats have been manufactured and sold by us (the original American Manufacturers) to almost all Universities, Colleges, Technical Schools and Industrial Concerns and have always given entire satisfaction.
Write for Bulletin C-5 BECK
3640-42 North Second Street
Spencer Microscope, No. 44H
With side-fine adjustment, lever type, is
It has become a standard for College and University laboratory work because of two special advantages:
I. A side fine adjustment with a
screw which has 34 threads
44H Microscope completely II. A side fine adjustment which equipped with 6X and 10x oculars, has a “Lateral-Travel”— tives, triple nose piece, quick screw
16 mm., 4 mm., and 1.8 mm. objecan index to its position rela- substage with condenser and iris tive to its limits.
44F Microscope, same equipThese coupled with other advan
as above but without the tages, optically and mechanically
1.8 mm. objective and with double make it an ideal microscope.
nosepiece instead of triple.
We Carry an Extensive Stock of Spencer
Microscopes and Accessories
FOUNDED 1852 584 Mission Street
SAN FRANCISCO, CAL., U.S. A. Scientific Apparatus of Every Description for all kinds of Laboratories. We
Specialize in Laboratory Equipment for Universities, Colleges,
Chemicals — Acids Glassware
“ We know how to pack for Export" Cable Address "BRAUNDRUG”
Los Angeles House All Codes Used
THE BRAUN CORPORATION
The Silverman Illuminator
"A New Eye for the Microsoope" a-Shows more detail. b-Presents a clearer and
better defined picture
methods of illumina
tion. d-Save very much valu
able time. Prevents eye strain, eye
fatigue and brain fag. f-Can be lowered into deep,
for very low power
microscope, ordinary or
binocular. A small circular tube lamp surrounds the objective and furnishes diffused and uniform illumination directly where it is needed. For sale by all the better dealers
Write for Bulletin 45-B LUDWIG HOMMEL & CO. 530-534 Fernando St. Pittsburgh, Pa.
A comparative test will speedily prove its excellence. Make one! We will be glad to furnish samples on request. All dealers in laboratory supplies carry these papers in stock.
H. REEVE ANGEL & CO.
INCORPORATED 7-11 Spruce Street
New York, N. Y.
Solo Mill Representatives for the United States,
Canada and Mexico
FRIDAY, JUNE 24, 1921
SINGLE COPIES, 15 CTS.
BINGHAM & CEN Viscometer and F tometer
SIMI D FORM
used, however, for testing the viscosi ny form of liquid, besides being ada or determining the plasticity of all plastic materials for which the initial pressure required is not more than that of a 10 foot water column.
The above is a simplified form of the apparatus (also supplied by us), which is recognized by the Bureau of Standards as the standard instrument for the determination of viscosity and plasticity.
The simplified apparatus consists essentially of the following parts:
2 pipe reservoir for stabilizing
regulating temperature. . . $22.50. Plastometer (Viscometer) with
2 wrenches and key...... $60.00. Besides the above essential parts, auxiliary apparatus may be ordered as desired.
For information in regard to auxiliary apparatus, and for further details, see E & A Bulletin No. 277, also Bureau of Standards bulletins Nos. 278 and 298, Proc. of A.S.T.M. Vols. 18 and 19; also Jour, of Amer. Chem. Soc., Vol. 38, P. 40, 1916, etc.