426 



CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 



No. 11280. 



No. 11284. 



No. F2177. No. 11300. 



No. 11304. 



No. 11308. 



11253. URANIUM NITRATE per ounce $0.60 



11259. URANIUM OXIDE (yellow) per ounce .50 



11261. WILLEMITE, Flourescent , per ounce .75 



11262. WILLEMITE, Phosphorescent per ounce 1.50 



11264. ZINC SULPHIDE, PHOSPHORESCENT, extra strong phosphorescence; produces very large scin- 



tillations with radium. In vials of 5 grams Per vial 2.00 



11265. ZINC SULPHIDE, PHOSPHORESCENT, strong phosphorescence. In vials of 5 grams. 



Per vial 1.00 



11266. ZINC SULPHIDE, TRIBOLUMINESCENT. Shows a markea luminosity when rubbed; is also 



phosphorescent. In vials of 5 grams Per vial 2.00 



11268. FLUORESCENT SCREEN, 65 x 45 mm 1.60 



11280. RADIOSCOPE, for detecting the presence o; radio-activity in waters, ores, etc., by viewing 

 scintillations on a phosphorescent screen. These scintillations are produced by the alpha par- 

 ticles emitted by the emanation evolved from radio-active substances. The instrument con- 

 sists of a jar for holding the substance under test, provided with a screw cap fitted with an 

 adjustable compound lens and a phosphorescent zinc sulphide screen. The emanation rises 

 from the jar into the cap and there causes scintillations on the screen. With each Badioscope 

 is supplied a quantity of high grade carnotite (radium) ore which may be used to learn the use 

 of the instrument. Size 20x7.5 cm 10.00 



11284. SPINTHARISCOPE, for showing the radiant energy of radium salt. Consists of a nickel-plated 

 metal tube, 19x35 mm, with a phosphorescent screen at one end and a high grade lens at the 

 other. Projecting from the center of the phosphorescent screen is a pin on the side of which 

 has been placed a small quantity of radium salt. With this instrument the scintillations pro- 

 duced on the phosphorescent screen by the constantly emanating alpha particles are shown in 

 the most marvelous manner. In order to observe this phenomenon in the day time the observer 

 should remain in a darkened room for a short time, so that the eye may become sufficiently 

 sensitive 4.00 



F2177. RADIOMETER, Crookes', illustrating phenomena of radiant heat. Mounted on glass base. . 



RAW MATERIALS, see list at end of letter W. 

 RAZORS, Section, see Microtome Accessories. 

 READING GLASSES, see Magnifiers. 



READING TELESCOPES, sec Catalog F of Physical Apparatus. 

 REAGENT BOTTLES, see Bottles. 



RECALESCENCE OUTFIT, see Furnaces, Electric; Pyrometers; or write for special informa- 

 tion. 



11300. RECEIVERS, Retort, glass, plain. 



Capacity, ee 125 250 500 



Each 50 .55 .65 



11304. RECEIVERS, Retort, glass, with tubulature and glass stopper. 



Capacity, cc 125 250 500 



Each . 75 .85 1.00 



11308. RECEIVER, Pauly's, for distillation in vacuum. 

 RECEIVERS for Blowers, see Blowers. 

 RECTIFIERS, see Electrical Instruments. 



With adapter and four bulbs 



1000 

 .75 



1000 

 1.25 



3.00 



