INSTRUMENTATION by Ralph H. Müller
New treatise on photoelectric phenomena strong in some areas of theory but weak in applications A RESULT of a lifelong interest in A sphotoelectric phenomena we turned with great interest to the second edition of an important book on the subject. More than 25 years ago Simon and Suhrmann wrote "Lichtelektrische Zellen und ihre Anwendung" at about the time that Hughes and DuBridge brought out their famous monograph on "Photoelectric Phenomena." The German treatise was highly informative and stimulating and emphasized practical matters to a greater degree than the more scholarly treatise of Hughes and DuBridge. It is highly improbable, and doubly unfortunate, that DuBridge, now president of the California Institute of Technology, will ever have the time or inclination to bring out a second edition. In the meantime, Simon and Suhrmann have edited a second edition, some three times larger than the first (737 + pages) with the new title "Der lichtelektrische Effekt und seine Anwendungen" with three collaborators, and published by Springer-Verlag, Berlin/Gottingen/Heidelberg ( 1958). The various sections include an introduction, the laws governing the photoemissive effect, the internal photoelectric effect, preparation of photoemissive crlls, construction and preparation of photoresistive cells and photoelements (barrier-layer cells), amplification by secondary emission, methods, and apparatus for photoelectric measurements, applications of phototubes to photometry, photoelectric image tubes and x-ray intensifiers, phototubes in television, special applications of secondary omission phenomena, special applications of phototubes. In the last section such things as the conversion of solar energy are dealt with. If the second part of the title—"und seine Anwendungen"—had been deleted, this would leave a first class
treatise on photoelectric phenomena. It deals, in considerable detail, with recent solid state theory and practice and with the important work of Shockley and his associates. The applications sections are hopelessly out of date and inadequate. Although electronic methods of amplification are mentioned, most of the circuitry is of the late twenties vintage. Analytical chemists will be sorely disappointed in the treatment of colorimetry and spectrophotometry. It may have been convenient and time-saving to copy the techniques of the first edition, but one would have to ransack a museum to find string electrometers, gold leaf electroscopes, and Dolezalek electrometers to make these measurements. The only recording spectrophotometer mentioned is the Hardy color analyzer, as described in the first edition, and no mention is made of the improvements which the General Electric Co. has made in Professor Hardy's original fine instrument such as the tristimulus computer attachment. We don't know how many thousand Beckman DU spectrophotometers there are in the world, how many Cary spectrophotometers or Warren Spectracords, but there is no hint of these things in this 1958 monograph. Of the six or eight distinct types of photoelectric refractometers which have been described in the recent literature, only two methods are mentioned and these are the two which have found the least application in precise work. We can hardly be accused of prejudice or bias if we mention that our early and pioneering work with the late H. M. Partridge on automatic photoelectric titrations (1928) is still accorded two whole pages, whereas the subsequent work, including Malmstadt's elegant second-derivative technique, is ignored. It comes as no surprise that the sec-
tion on image converter tubes or "Bildwàndler" is fairly well covered. In the early days of World War II, the German military developed these devices for nocturnal vision and the British and Americans soon came out with similar instruments including the famed Sniperscope. The authors on the very first page neglect one of their countrymen, for it is generally agreed that Heinrich Hertz discovered the photoelectric effect. His greater interest in the propagation of electric waves took precedence over the incidental photo effect. To be sure, Hallwachs made the first systematic study of the effect and to a large and almost exclusive degree the Germans speak of photoelectricity as the Hallwachs effect just as they usually prefer Rôntgenstrahlen to the term x-rays. These lacunae are curious because they are describing what for a long time was an essentially German science —i.e., Hertz, Hallwachs, Elster and Geitle, Lenard, and Einstein. To be sure, it was an American, Millikan, who gave the first precise experimental proof of Einstein's equation Ve = Ac —
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One is almost tempted to say that the book's limitations arise from the fact that it is written by physicists. There is no doubt that the most elegant examples of photoelectric photometry and spectrophotometry have been due largely to instrument-minded chemists. It cannot be said that the treatment is limited to German practice, because there are extensive references to work by R.C.A. and DuMont in this country and to Mullard, Electrical Musical In dustries, and Cossor in England. There is also an extensive listing of photomultiplier tubes of American, English, French, German, Swiss, and Russian manufacture. VOL. 3 1 , NO. 11, NOVEMBER 1959
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It recalls to mind a charming tale about the latter years of Einstein's life at Princeton. After the death of Mrs. Einstein the professor's household was managed by a distant cousin. With ef ficiency and vigor she chased away the idly curious, the salesmen, and promot ers and Herr Albert's attention could be devoted to his calculations and to his violin. But one day this worthy woman rebelled and announced that he must explain this relativity business to her. "Morning, noon and night, when distinguished visitors come here, it is nothing but Relativity!" Quietly and blandly Einstein asked— "Anna, you know how to make Spaetzle? (a variety of German egg dumplings)." "What a question, Al bert," said she. "The very best, as you well know." "Good," said Einstein. "From now on, in this household, you will be in charge of Spaetzle—I will han dle the Relativity."
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ANALYTICAL CHEMISTRY
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We are inclined to believe that these German authors are not alone in neg lecting technical details, even in a book which purports to deal partly with applications. The epidemic seems to have struck our country some time ago. Some au thors who have set themselves the task of writing a text on methodology or techniques, suddenly feel the need of dressing it up with differential equa tions, matrices, Boolean algebra, and other elegant intellectual ornaments and often to the degree that little room is left for the sordid technical or exper imental details. The idea seems to be that if the general details are sketched out any dummkopf can figure the rest out for himself. The mathematicians seem to be able to stick to their lasts and if they write a monograph on the Space Groups Ε of Frechet they seem to feel no urge to explain how these might be used to reduce one's income tax or how to pay off the mortgage. Can we not do one thing or another and stick to the original objective?
lNC.
COLORADO
New Instrumentation Treatise
Word has come to us from the pub lisher (McGraw-Hill) that the treatise on instrumentation by Kurt S. Lion of Massachusetts Institute of Technology has appeared. We had the privilege of reviewing this book in manuscript form and remember, with delight, the excel lent treatment of many important top ics. As we recall it, there was a fine bal ance between the theoretical principles and the experimental details of these techniques. Many of these things will be of direct interest to the analyst and we await our copy here in the South west with great interest.
