I
nn U J L I u n I UGU n L a c n u i i NALYTICAL
INSTRUMENT^
are
be-
A,. rmng more elegant, more complex,
and, of neeshy, more expensive. To an inemwing degree they are becoming automated and for some time, some of them have been made compatible with computers. All this is good new8 in industry and in large m a r c h laboratories. It is making life increasingly difficult for the professor attemp& ing to teaeh instrumental analysis. Many of these instruments are far too complicated and compact for the student to grasp their construction and mode of operation. Conversely, it would be silly if the manufacturer attempted to “breadboard” them for easier comprehension. Wiring diagrams and schematies are helpful of course, hut they leave much to be d e aired. More than a dozen excellent textbooh on instrumental analysis are available. Quite sensibly, most of them are tailored to the equipment likely to he found in a fairly well equipped colI.ae laborator~. Of necessity the more wmplex instruments must either be omitted, or described in sufficient detail to explain their nature and functions with little hope that the student will have an opportunity to u8e them. From time to time we have described various systems which have been devised to afford the student practical experience in the use of analytical instruments. The modular system, in which a variety of more or less standard units can he interconnected in a variety of combWtiOM, parsesreS t W 0
ad-
vantages. I. It can permit the assembly of many analytical instruments at far less cost than an array of singlepurpase complete instruments. 11. The function, construction, and performance of each individual module are more d i y understwd. This time we wish to describe a sy% tern about which we have heard many enthusiastic reports. The A. R. F. Modular Instrument Concept is manufactured by A. R. F. Products, Inc., Gardner Road, Raton, N. M. The A. R. F. Analytical Instruments were developed by Dr. Galen W. Ewing, Professor of Chemistry a t Seton Hall University, South Orange, N. J., when he was here at New Mexico Highlands University in Las Vegas. His investigations a t that time were conducted under the Course Content Improve-
ment 4 0 1 1of the National Science Foundation. Dr. Ewing is also Clemi d Instrumentation Fditor of the Journal of Chemicnl Educdion. Figure 1 shows Dr. Ewing with one particular combination of modules being used for thermometric titrations. At the left a peristaltic pump delivers reagent at a constant rate to the mlution. Temperature change is measured with a thenuistar probe connected to the Wheatstone bridge. Bridge unManee is fed to an operational amplifier and thence to an output meter or r e corder. Figure 2 shows mme of the same modules along with an absorptiometer module (foreqonnd). This is a eomhined spectrophotometer and filter photometer including a di5raction grating attachment. The A. R. F. analytical modules offered at present include an electrometer, voltage source, current source, potentiostat, de meter, ac wbeatstone bridge, thermistor probe, operational amplier (includes ramp generator), timer, recorder, pump abmrptiometer, and electrical accessories such as single- and 2-con-
ductor eahles, and 12 precision resistor shunts. In particular we are impressed with Ewing’s “Analytical Instrumentation, A Laboratory Guide for Chemical Analysis,’’ Plenum Press, N. Y., 1966, which serves as a manual for the use of these systems. It deals with instrumentation and is not cluttered with l e a ~ e ddigressions of thermodynamics, electrode vagaries, and other fundamentals which the student ought to h o w before he tackles analytical instrumentation. His own “Instrumental Methods of Chemical Analysis” 2nd Ed. McCraw-Hill. N. Y., 1960, is among the 16 standard tex& to which he makes frequent reference, for such points in fundamental theory with which the student may refresh his memory. Conversely, there is an excellent treatment in Section V of the manual entitled Experiments in Instrument Evaluation in which each module is tested critically in terms of purely physical or electrical terms. To our way of thinking, this is the way an instrument or component should be studied, checked, and calibrated. It
I Figure 1. Dr. Ewing with modules set up for thermometric tirations
+t
I
Figure 2. Analytical instrumentation modules including an absorptiometer module (foreground)
is always preferable to puttbg a standard solution in the hopper and seeing if thimgs turn out well. In p r t IV (Analytical Experiments) there are 17 well chosen experiments to convince the student that these instrumental techniques can indeed afiord the analyst a great variety of a p p m h e s to the subject. In our opinion A. R. F. Products has done a commendable job in producing this equipment. It can be expected that additional items will appear in the futnre.
J. Robert Oppenheimer
Newswe& for March 6,1967, p. 98, in commenting on the death of this ge.nius said, “When J. R~bertOppenheimer died on February 18, after a long battle with throat cancer at his home m Princeton, N. J., the atomic age lost one of its central d-if victims.” Time magazine also dwelt eatensively on the eareer and misfortune of this man. Both give the imp d o n that those deep feelin@ which led him to fear the development of the H-bomb and convinced him that nuclear weapon proliferation would not enhance national seeurity in a world where wars would still he fought with conventional weapons, made him a prophet, in the lisht of present events. They seem to confirm the 012 adage that ‘‘a prophet is not without honor, save in his own country.” It w88 our privilege to know him intimately dnring h i graduate days m GZittingen in 1921. I n those “golden days of atomic physic? as many called it, one made the Grand Tow of Europe. For a physicist this meant a visit to Rutherford at the Cavendsh, stops at Leiden and Utrecht, to see Sommerfeld at Munich and as long a stay as possible in Gtttingen. On the way home, one had to visit Niels Bohr in Copenhagen. At 23, @pie was concluding his doct o d research in theoretical physies with Max Born. Our own professor, James Franck, appeared one day in formal attire to announoe that be waa attending Oppenheimer‘s oral &ation. A few hours later he returned, sat on a laboratory stool, fannmg hun-
self with hi top hat, and muttered “Mein Gott, weis’ der Kerl Phys&!” You know Herr Miller, I just got ont of there in the nick of t i m e h e started asking me questions!” This intellectual enfant terrible staggered the imagination. Strangers, at first considered him an imposter-he couldn’t possibly know so much about most everything. They would deliberately misquote a lire from a current American, German, or French novel, only to be given a polite smile and the remark “Oh, you mean . . . . .” and a t once get the exact quotation. During the munmer of that year, visitors arrived almost daily-E. 0. Lawrenee and Je5e Beam, then from Yale, Wood and Peters from Baltimore, Dirac from Cambridge, Pauli from Vienna. Most of them wanted to talk to O p p heimer. He and Dirac had much in common. The latter once t e m d him about his studies in the Bhagavad-Gita and his ventures in writing poetry. ‘T am astonished at your interest and greatly i m p d by the poetry but for the life of me, I can’t understand it.” “As I see it, a physicist takes a phenomenon which no one has ever head of and tries to explain it so that anyone can understand it, w h e w a poet d m just the opposite.” In relatively simple things he was as naive as a child. He was astonished a t our average ahility to do glass blowing and stated k t l y that he could never hope to learn such a thing. Small wonder that this man, suave, dtivated, and perfectly at ease could enlist the hest & o r b of top flight seientists in the fantastic pmblem which was unfolding on thc lonely mesa a t Los Alamos. Perhaps his more proper role would have been entirely at the pleasant and peaceful Institute for Advaneed Study in Princeton, where he presided genially in the company of poets, economists, philosophers, mathematicians, and other uncommitted scholars. Ivory towers ought to be resurrected for such men, even if they only appear once or twice a century. A war, with the manifold horrors, injustices, and ill tempers which it engenders, can strike down the best of men.
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