NEW BETHLEHEM GLASSBLOWING KIT with MANUAL for
Chemists,
Physicists,
Modify
Engineers
Apparatus
and
Systems,
Others
To Construct,
Glass to Metal
FROM
PRICE $ 2 4 6 . 0 0 Write for
DEALER
B u i . K-60
The Bethlehem Glossblowing KIT Contains Twin Tubing (2 sizes) Didymium Goggles Vernier Calipers Tungsten Carbide Knife Carbon Hex (2 sizes) Rollers (dual purpose) Crayon (2)
Assorted Corks Asbestos Paper (2 sizes) Carbon Rods (2 sizes) Wire Screen (3 pieces) Tweezers (2 sizes) Ribbon Fire (gas-oxygen) Ruler
Brass Shaper Beeswax Tungsten Tool Sodium Nitrite Pluro Stopper Metal Kit Box Manual
BETHLEHEM APPARATUS COMPANY, INC. HELLERTOWN, PA. Circle No. 32 on Readers' Service Card MC&B
Spectroquality
Solvents
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Write for new Chart Showing U. V. and I. R. Transmittance of Spectroquality Solvents This convenient 14" χ 17" wall chart shows maximum Ultraviolet and Infrared transmittance of our complete line of 26 MC&B Spectroquality Solvents. We'll be glad to send you a copy, without charge. Our booklet "Spectrophotometry and the Chemist", is also available on request.
Matheson Coleman & Bell D i v i s i o n of T h e M a t h e s o n C o m p a n y , I n c . N o r w o o d ( C i n c i n n a t i ) , Ohio; E a s t R u t h e r f o r d , N e w J e r s e y 28 A
·
ANALYTICAL CHEMISTRY
not be detected by this method using the flame as an atomizer.
Repair,
Seals
YOUR
Asbestos Work Board Hot Glass Rest Sharp Flame Hand Torch Torch Stand Blowhose (2 extra mouthpieces) Spandle Carbon Flat
REPORT
Commercially Available Equipment
Much work has already been done to establish atomic absorption as a reliable technique with fun damental advantages over emission techniques. However, the pro cedure is new and the only equip ment available commercially is at best modified flame photometers or spectrophotometers. In Australia, Walsh has provided a prototype suitable for most ap plications. This equipment (Fig ure 3) embodies multielement hol low cathodes, source modulation, a burner designed for this work, and a simple monochromator and detector system which can be pur chased quite cheaply. The main theme of his equipment is sim plicity. It is to be hoped that future manufacturers of such in struments will maintain this sim plicity and low cost, at least for simple routine applications. The only other source of equip ment is provided by Hilger and Watts. This equipment (Fig ure 4), is a conventional Uvispek spectrophotometer to which has been added an attachment consist ing of a burner and hollow cathode attachment. This equipment does not embody source modulation, and although it can still be used for many purposes, any emission sig nal from the flame is not elimi nated from the final signal and would, of course, confound the re sult obtained. Such emission would be subject to all the interferences encountered in flame photometry. In this country, Perkin-Elmer has already shown interest in the method. To date, its equipment has been restricted to instruments suitable for research in assaying the value of the field. Figure 5 shows a modified Model 13 as used at Perkin-Elmer and at Esso Re search Laboratories, Baton Rouge, La., for work in this field. This equipment embodies all the re quirements for research on this sub ject—e.g., modulation, high resolu tion, single-beam, and doublebeam circuits and special light-
