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There was dose collaboration between users and instrument people, with much useful feedback from the former. I remember an early Ohio State Conference when some of the attendees were sitting outside the residence hall on a very hot summer evening. Van Zandt Williams told us that Perkin Elmer was designing a new double-beam instrument (which became the Model 21), and he wanted opinions on what size the chart paper should be. People held out their hands to indicate their preference, and Williams went around with a tape rule, measured the spacings, and jotted them in a notebook. That, in part, accounts for the size of the paper drum on the Model 2 1 .
a finger.) He says nothing, however, about the use of liquid paraffin oil. The Nujol mull technique was un known to Wright when he wrote his 1941 survey paper (23), and he was well informed on such matters. How ever, it was mentioned by Barnes et al. (17) in 1943. Robert S. McDonald recently told me that he believes he made the first Nujol mull as the re sult of a suggestion made by Barnes. McDonald was working in the Amer ican Cyanamid Co. IR laboratory in 1942 when a number of phthalocyanine samples, which were intracta ble, were submitted for examination. A paint laboratory happened to be just around the corner. Workers sus pended pigments in paint vehicles by g r i n d i n g the s l u r r y between two glass disks 6 - 8 in. in d i a m e t e r . Barnes suggested that McDonald try this method for the phthalocyanines b u t u s e Nujol for t h e liquid. It w o r k e d like a c h a r m , a n d t h e y quickly found that they could scale down the procedure. Although they did not describe the method in detail in the literature, the 1943 paper m e n t i o n s it casually. Thus the method seems to have been introduced in 1942 or early 1943. In terestingly, the collection of spectra that Barnes et al. presented (17, 18) does not contain that of Nujol. It is a pleasure to be able to give credit at long last to the people who originated this useful technique; it is long over due. P e r h a l o g e n a t e d oils, developed during and just after World War II, are a useful complement to Nujol. Their use for IR mulls seems to have
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been first described by Crocket and Haendler in 1959 (24). The use of KBr pressed disks was first described in 1952 by Sister Mir iam M. Stimson of Siena Heights College (Adrian, MI) (25). She devel oped the procedure while looking for a technique to obtain both UV and IR spectra on the same sample. It has been widely used in the IR region but scarcely at all in the UV region. Attenuated total reflection (ATR) was developed i n d e p e n d e n t l y by Fahrenfort (26) and Harrick (27) be tween 1959 and 1960. It has been es pecially useful for thick samples, strongly absorbing samples, and sur face studies. Matrix isolation (freezing a sample at about 10 Κ as a very dilute solu tion in an inert medium such as ar gon) was introduced independently in 1954 by Norman and Porter (28) and by Whittle, Dows, and Pimentel (29). Variable long-path gas cells, origi nally devised by White (30); the dia mond high-pressure cell, developed by Weir, Lippincott, Van Valkenburg, and Bunting (31); and diffuse reflec tance, developed by Willey (32) and by Fuller and Griffiths (33) have also been important developments. All of these things constitute what I have called "the infrastructure of IR s p e c t r o m e t r y " : prior k n o w l e d g e ; availability of good optical compo nents; great improvements in instru mentation; training courses, books, and meetings; and an unusually wide range of sample-handling methods. They all contributed to the feasibility and rapid acceptance of commercial IR instruments. I would like to express my warm appreciation to the many friends who provided information for this paper, especially Norman B. Colthup, Fre derick Halverson, Robert W. Hannah, and Rob ert S. McDonald. Preparing this has been a nos talgic experience because it led me to think about some events of long ago, and that brought a flood of pleasant memories. I therefore extend my sincere thanks to the organizing committee of the Waters Symposium for inviting me to participate. References (1) The Random House Dictionary of the En glish Language, 1968. (2) a. Jones, R. N. In Chemical, Biological, and Industrial Applications of IR Spectros copy; Durig, J. R., Ed.; John Wiley and Sons: New York, 1985; Chapter 1, pp. 1-50. b. Jones, R. N. European Spectros copy News 1987, 70, 10-20; 72, 10-20; 74, 20-34. (3) Nichols, E. F.; Tear, J. D. Astrophy. J. 1925, 61, 17-37. (4) Lecomte, J. Le Rayonnement Infrarouge; Gauthier-Villars: Paris, 1949; Vol. 2, p. 395. (5) a. Strong, J. Phys. Rev. 1930,36, 1663-
