354 BELL SYSTEM TECHNICAL JOURNAL 



for every 10 carbons. It was not until much later that it was postulated 

 that rubber, inasmuch as it had the same hydrogen to carbon ratio as 

 isoprene obtainable from it, was a compound in which many isoprene groups 

 were in some manner combined together. Thus, Harries about 1904 was 

 inclined to regard rubber as a sort of association complex representing a 

 combination of relatively small ring molecules held together by van der 

 Waals' attractions^ This same view of polymers as associations of small 

 molecules was also applied to cellulose by well-known carbohydrate chemists 

 both in England and in Germany. 



The influence of the contemporary colloid chemists helped to promote this 

 idea. Even the term "micelle", applied by them to soap and other aggre- 

 gates, which are in fact van der Waal's or ionic associations, was unfortu- 

 nately adopted to describe the structure of many of the organic polymers. 

 In addition, early x-ray studies on natural polymers, because of a misinter- 

 pretation of the diffraction patterns, lent further support to these views. 

 For some reason or other it was not appreciated by workers in the field that 

 the x-ray unit cell did not necessarily mark the boundaries of the organic 

 molecule. Hence, since the unit cells appeared to be small, many errone- 

 ously concluded that the molecules were small also. It is to Sponsler and 

 Dore-, working in this country in 1926 on the x-ray structure of cellulose 

 fibers, that we must give thanks for being the first to realize the incorrectness 

 of the older x-ray deductions and to postulate a long primary valence chain 

 structure for cellulose. 



The realization that natural organic polymers really consisted of very 

 long chains of primary valence bound atoms, in the strictly organic chemical 

 sense, came surprisingly slowly. Staudinger in Germany beginning about 

 1926 was most insistent on this view^ although others including Meyer and 

 Mark were developing the same conception. As early as 1910 Pickle in 

 England had conceived of such a chain type of molecule for natural rubber 

 but unfortunately did not follow it up. As the idea of molecules of large 

 size grew, it became more and more popular to try to measure them. Also 

 there was much effort given to working out the details of the"cr>^stal 

 structure" of the natural products insofar as they could be regarded as 

 crystalline. Here again was an opportunity for argument which is still 

 going on today: just what do we mean by the term "crystalline" when 

 applied to these substances? The answer seems to be that we have all 

 degrees of organization of the molecules, or more correctly parts of molecules, 

 in pol>TTiers from the completely chaotic or amorphous in some to highly 

 ordered or what may be called crystalline arrangement in others. We shall 

 have occasion to come back to this subject in our later discussion. 



It was logical that the interest of scientists in the constitution and struc- 

 ture of polymers should be lavished on naturally occurring high polymers 



