28 A
ANALYTICAL
WILL Laboratory
Equipment
NEWS
OF THE MONTH
DYNA-CATH High-speed magnetic mercury cathode Removes metals rapidly and completely, w i t h clean m e r c u r y surface a n d m i n i m u m r e - s o l u t i o n of d e posited metals. For 115V, 50-60 cy/AC. W r i t e for D y n a - C a t h Bulletin 2 5 0 . 1243 IT..., $460.00 1 2 4 3 3 T * Anode, Platinum (2 required) 1 2 4 3 4 T * Cathode Connector (2 required) * (Price subject to current platinum mkt.)
INSTRUMENT BRUSH Cleans by radio-activity (Static M a s t e r ) Cleans bal a n c e s , m i c r o s c o p e s , film a n d optical apparatus. Removes d u s t by d e s t r o y i n g static sur face a t t r a c t i o n . U t i l i z e s h a r m less r a d i o - a c t i v e P o l o n i u m . G u a r a n t e e d for I yr. W i d t h I " . 6921T $4.95
WATER-TAP FILTER Works without refills P r o d u c e s crystal c l e a r taste ful w a t e r free f r o m c h l o r i n e , rust, s e d i m e n t , o d o r s . Fits s t a n d a r d w a t e r tap. C l e a n s by r e v e r s e flushing. H a s l o n g life. S p e c i a l a d a p t e r fits standard hose connection. 13366T—Filter $9.95 13368T—Hote adapter set $1.50
POLISHER Low speed precision finishing ( B u e h l e r ) P r e p a r e s b e t t e r s p e c i m e n s for m e t a l l o g r a p h y . Selective s p e e d s , 150250 R P M . Complete with 8" balanced b r o n z e w h e e l a n d b a n d to h o l d p o l i s h i n g c l o t h . S t u r d y cast flanged b o w l w i t h drain, cover, removable hand rest and s p l a s h r i n g . Ball b e a r i n g m o t o r . For 115V, 60 cy/AC. 1 7 8 8 6 $275.00 Complete Buehler line of cutters, presses, grinders, surfacers, polishers and abrasives.
FAST REPAIR SERVICE
Send your microscopes and Beckman instruments to WILL at Rochester for repairs. Our t r a i n e d technicians give you fast, e x p e r t r e p a i r service at lowest cost. Five convenient office-warehouses a r e r e a d y t o serve you. Contact the one nearest you.
FURNACE For high temperature combustion ( L e c o ) O p e r a t e s at 2 6 0 0 F c o n t i n u o u s l y a n d to 3000 F intermittently. T w o tube. T h i c k 6 l /2" i n s u l a t i o n , heavy cast a l u m i n u m case p e r m i t c o m f o r t a b l e w o r k at h i g h t e m p e r a tures. For 110V, 50-60 cy/AC. 14576T $745.00
MICROSCOPE Wide field — l o w cost (Bausch & Lomb) G r e e n o u g h type, verti cal e y e p i e c e , s t e r e o scopic binocular prism. C o m p l e t e w i t h I set 10 X p a i r e d H u y g e n i a n e y e p i e c e s ; 2 sets, Ι . Ο χ a n d 2.0 paired objec tives. T o t a l magnifica t i o n , 10 a n d 20 d i a m e t e r s . I m m e d i a t e deliv ery. 18446 $260.00 We handle a complete line of laboratory optical equipment.
DEMINERAL1ZER For mineral-free water (Barnstead Bantam) Demineralizes w a t e r at 5 t o 8 G P H in c o n t i n u o u s flow from any w a t e r supply, without heat. N e w d i r e c t - r e a d i n g dial tells quality of w a t e r p r o d u c e d . R e n e w a b l e cartridge eliminates regener ating, backwashing, rinsing. For 115 V, 5 0 - 6 0 c y / A C . 1 1 8 7 1 — without cartridge... $ 8 3 . 0 0 11872—cartridge! only. Each—$12.00, Carton of 6 $ 5 7 . 6 0
Order from your nearest WILL office-ware house. More data on these items w i l l be sent at your request. PHONE — WRITE - WIRE — TELETYPE
WILL CORPORATION
Rochester 3 , Ν . Υ.
WILL CORPORATION
New York 12, Ν. Υ.
WILL CORPORATION of M d . . Baltimore 1, M d . SOUTHERN SCIENTIFIC CO., INC.. Atlanta 1, G a . BUFFALO APPARATUS CORP.. Buffalo 5, Ν . Υ
CHEMISTRY
INSTRUMENTATION In attempting to measure the reflect ance spectrum of such systems, one en counters the difficulty or complication that not only is the incident radiation reflected, but components also appear which are excited by the incident radia tion. The problem may be treated by observing that the reflected beam for a monochromatic incident beam consists of two parts—one having the wave length of the incident beam and another part separated in wave length from the normal beam, spread over a fairly nar row portion of the spectrum and having a maximum at a wave length which re mains fairly constant as the wave length of the incident beam changes. This technique is discussed by J. E. Tyler and Γ. P. Callahan [J. Optical Soc. Am., 41, 997 (1951)]. Stellar
Photometry
An excellent discussion of stellar photometry is given by the renowned astronomer Joel Stebbins [Sci. Amer ican, 186, 56 (1952) ]. Altliough written for the intelligent layman, it describes some of the most recent techniques. Among these is the photoelectric "onoff" method in which a rotating pinhole alternately superimposes a star image on the "black-sky" background, both of which are viewed by a photomultiplier. The modulated component permits measurement of the intensity of some stars in broad daylight. Conversely, since the secular variation of brightness is known for some stare, the method may be used for studying the variation in atmospheric haze. Automatic celes tial navigation was developed some years ago and is now in a high state of practicability. The analyst can take renewed hope in tackling his relatively simpler photometric problems if he notes the difficulties which have been overcome by the astrophysicists. They were among the first to resort to re frigerated phototubes as a means of in creasing the signal to noise ratio. Progress is truely paced by instru mental developments. The earliest Ra man spectra were photographed with fast spectrographs and with exposures running in some cases to days. It is now possible to record the contour of a single Raman line wnth high precision and to determine the area under the re cording. Such information is yielding analytical information at concentrations several orders of magnitude smaller than was possible 10 years ago.
