14 FREDM. UBER 



advances in even his own field of research by browsing occasionally in 

 a library or by depending on the receipt of reprints from the w^orkers 

 themselves. Accordingly, one should plan to make systematic use 

 of some or all of the following categories of assistance wath reference 

 to his special field of research {19, p. 74): (a) index journals; (6) 

 abstracting journals; (c) annual reviews and yearbooks; {d) recent 

 advances series on specific topics; and (e) review journals. For those 

 without experience in library research, a list of "guides" to-the litera- 

 ture in the various sciences is included in the bibliography {13-18). 

 These contain helpful suggestions as w^ell as source lists of specific 

 reference materials for the individual sciences. 



In connection with reading the older literature, a word of caution 

 may be helpful, particularly with reference to numerical data. Over 

 the years, a marked change has taken place in the value of the numeri- 

 cal physical constants that enter into various computations. Hence, 

 recalculation is in order before making comparisons with many of the 

 earlier results. Common usage for w^ords and symbols also change. 

 A good example to illustrate the point is the recently suggested change 

 in nomenclature involving the use of l and d instead of I and d for 

 labeling the amino acids and sugars {25). The opposite name from 

 the one formerly employed results in some cases, to the confusion of 

 the uninitiated. Nomenclature changes for the genus and species 

 of microorganisms, especially bacteria, are not infrequent and are 

 likewise confusing. 



There is no unique way of keeping in satisfactory contact with 

 research currently in progress, particularly w'here investigative 

 activity in an experimental field is world-wdde. With respect to 

 investigations under way wdthin one's own country, valuable informa- 

 tion can be gleaned from attendance at scientific meetings and perhaps 

 from correspondence, but, with the exception of very limited fields, 

 the coverage will be inadequate at best. There has been an increasing 

 tendency to organize scientific workers into small groups on the basis 

 of their interest in specialized fields of research. Recent examples of 

 this are such organizations as the Electron Microscope Society, the 

 Society for X-ray and Electron Diffraction, and the Phycological 

 Society. Informal symposia on specialized topics of active research 

 interest are becoming increasingly frequent and should go far tow^ard 

 keeping scientific specialists up-to-date. The proceedings of such 

 symposia are often published, but only after an appreciable lapse of 

 time. There seems to be some danger that the great effort required to 



