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Recensiones. Libri et Synopses. Harrison, 0. R., R. c’. Lord and J. R. Loofboerow: Practical Spect,ros- copy. New York: Prentice-Hal1 1948. 605 pp. This volume, compiled jointly by a physicist, a chemist and a bio- physicist, attempts to give a comprehensive view of spectroscopy a8 it is used in these three branches of science. They have avoided both the historical and the exhaustive treat,ment of the subject, and have included matters of detail about t(heory and technique but not about applications of the methods described. After an int,roduc+ory survey of the scope of spect,rosropy the next four chapters describe t,he instruments used principally for emission spec- troscopy. As one would expect from workers at’ the Massachusetts Insti- tute of Technology, this is a first-class review of the subject, a.nd the bib- liography is up bo dat’e as far as 1947, at least for American work. The comparison of prism a#nd grating instruments is discussed at’ lengbh, and in an unusual table the aut,hors present, the numbers of lines per inch re- quired on a concave grating to mat’ch the dispersion of a 6Q” prism of quartz or of glass at several wave-leng:bhs. The chapter on t,he care and adjustment of grating and prism instruments reveals the extra work nec- essary to get the best from a grat’ing as compared with a, prism spectro- graph. The chapter on the illumination of the spect.rosrope covers t’he subject lucidly, except for a slip on p. 130 where a line appears to be missing from the text. The use of photography in recording upectra is discussed with- out mention of reciprocity-law failure, this subject (though not in the Index) is dealt wit’h briefly in t,he chapter on Photographic Photometry. Both non-recording and recording micro-densit,ometers are briefly de- scribed in the same chapter. The origins and underlying regularities of at,omic spectra and of mo- lecular spectra are dealt with in t#wo long chapters, which give an admi- rable survey but are not a8 well provided wit’h lit,erature-reference8 as other parts of the text. Absorption spect,rophotometry is not’ entirely segregated from emis- sion spectra, but is dealt wit,h in three chapt,ers: one for the ordinary range of ultra-violet and visible, one for the infra-red and one for t’he va- cuum ultra-violet region. Technique8 of absorption measurements are divided between t,he sections on “ The measurement of spect’ral intensi- ties ” and “ Absorption Spectrophotometry ” so t,hat t,he former covers modern met’hods of non-phot,ographic measurement for both emission and absorption spect’ra for t)he whole range of wave-lengt,hs from 2000A to 25 p. 40

Practical Spectroscopy : Harrison G. R., R. C. Lord and Loofbourow: New York: Prentice-Hall 1948. 605 pp

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Page 1: Practical Spectroscopy : Harrison G. R., R. C. Lord and Loofbourow: New York: Prentice-Hall 1948. 605 pp

Recensiones.

Libri et Synopses.

Harrison, 0. R., R. c’. Lord and J. R. Loofboerow: Practical Spect,ros- copy. New York: Prentice-Hal1 1948. 605 pp.

This volume, compiled jointly by a physicist, a chemist and a bio- physicist, attempts to give a comprehensive view of spectroscopy a8 it is used in these three branches of science. They have avoided both the historical and the exhaustive treat,ment of the subject, and have included matters of detail about t(heory and technique but not about applications of the methods described.

After an int,roduc+ory survey of the scope of spect,rosropy the next four chapters describe t,he instruments used principally for emission spec- troscopy. As one would expect from workers at’ the Massachusetts Insti- tute of Technology, this is a first-class review of the subject, a.nd the bib- liography is up bo dat’e as far as 1947, at least for American work. The comparison of prism a#nd grating instruments is discussed at’ lengbh, and in an unusual table the aut,hors present, the numbers of lines per inch re- quired on a concave grating to mat’ch the dispersion of a 6Q” prism of quartz or of glass at several wave-leng:bhs. The chapter on t,he care and adjustment of grating and prism instruments reveals the extra work nec- essary to get the best from a grat’ing as compared with a, prism spectro-

graph. The chapter on the illumination of the spect.rosrope covers t’he subject

lucidly, except for a slip on p. 130 where a line appears to be missing from the text. The use of photography in recording upectra is discussed with- out mention of reciprocity-law failure, this subject (though not in the Index) is dealt wit’h briefly in t,he chapter on Photographic Photometry. Both non-recording and recording micro-densit,ometers are briefly de- scribed in the same chapter.

The origins and underlying regularities of at,omic spectra and of mo- lecular spectra are dealt with in t#wo long chapters, which give an admi- rable survey but are not a8 well provided wit’h lit,erature-reference8 as other parts of the text.

Absorption spect,rophotometry is not’ entirely segregated from emis- sion spectra, but is dealt wit,h in three chapt,ers: one for the ordinary range of ultra-violet and visible, one for the infra-red and one for t’he va- cuum ultra-violet region. Technique8 of absorption measurements are divided between t,he sections on “ The measurement of spect’ral intensi- ties ” and “ Absorption Spectrophotometry ” so t,hat t,he former covers modern met’hods of non-phot,ographic measurement for both emission and absorption spect’ra for t)he whole range of wave-lengt,hs from 2000A to 25 p.

40

Page 2: Practical Spectroscopy : Harrison G. R., R. C. Lord and Loofbourow: New York: Prentice-Hall 1948. 605 pp

620 Reoensiones.

Qualitative and quantitative spectrochemical analysis each receive one chapter, and here again the references to published papers are very selective, not even including the major bibliographies. For quantitative analysis the use of logarithmic sectors is referred to, without going on to their improvement as step-sectors or step wedges, but the survey extends to the modern use of Geiger-Miiller counters and electron-multiplier photo-cells.

A final section on interference spectroscopy explains how the limits of resolving power can be reached, and why this sort of measurement is useful. The book is one which will be welcomed by every teacher of spec- troscopy, and by many students and teachers of associated subjects. It is not a text-book for the industrial spectroscopic laboratory unless this is also a research laboratory.

E. H. S. van Someren (Broxbourne).

Venable, W. M.: The Interpretation of Spectra. New York: Reinhold Publ. Corp. 1948. VI, 200 pp. $ 6.00.

Im erkl5irten Gegensatz zu der Quantenmechanik versucht der Vf. eine Spektrallinienklassifikation, die eine Deutung der Emissions- und Absorptionserscheinungen unter Beibehaltung der klassischen elektro- magnetiachen Vorstellungen zullsst. Nach jahrzehntelangem Probieren und Rechnen unter stsndiger Beniitzung der schon vorliegenden Einord- nungen bietet er eine Klassifizierung des Wasserstoffspektrums, die einheitlich Linien- und Viellinienspektrum dieses einfachsten Elementes darstellen kann mit Hilfe von zwei Haupttermen, cca )) = 109678 cm-1 und ((b )) = 117 754.43 cm-l, die in gesetzmLssiger Weise kombiniert, die entsprechenden Frequenzen ergeben. Nach Durchbesprechung einiger reprgsentativer Spekt’ren und einem Exkurs iiber RGntgenspektren legt er auf Grund seiner Ergebnisse ein neues Atom- und Molekiilmodell vor und spricht zum Schluss noch iiber Kernstruktur und LichtBther.

Der Vf. ist der Ansicht, dass Atome nur kontinuierliche Spektren aussenden kiinnen, dass die Linienspektren auf (( lineare )) Molekiile zu- riickgehen. So werde die erste Lymanlinie von einem zwei-atomigen li- nearen Molekiil erzeugt, die zweite Linie von einem drei-atomigen, die dritte von einem vier-atomigen usf. Balmer- und Paschenfrequenzen kijnnten aufgefasst werden als Differenzen von Lymanfrequenzen. Das Viellinienspektrum des Wasserstoffs habe seinen Grund in Molekiilen, die neben der (( a ),-Form (die allein verantwortlich sei fiir die Hauptaerien) noch die (( b ))-Form enthalten. Auf weitere Einzelheiten kann hier nicht n&her eingegangen werden.

Wenn such nicht abgeleugnet werden ~011, dass der Vf. eine ungeheure Arbeit und vie1 Scharfsinn aufgewandt hat und tatsachlich manche Li- nien einordnen kann, die sich bisher einer Klassifizierung entzogen, SO

ist es doch (( praktisch ausgeschlossen 11, (( die bei der Anregung der Spek- trallinien sich ergebenden Erfahrungstatsachen wesentlich anders zu

deuten als durch die beiden Grundpostulate der Bohrschen Theorie ))