The Differentiation of Occupations

ten subcategories were needed. By 1940 there were thirty, while by 1970 the number had risen to seventy-five (see Table 2.1 for the 1970 list). Certain of the subcategories show remarkable endurance over time. Assayer appeared at least as early as 1880 and was still in use in 1970, while analytical chemist is represented from 1910 to the present. Even so, the separately recognizable occupation of gold assayer is listed from 1910, while the 1970 classification recognizes not simply analytical chemists, but also chemical analysts, food analysts, and pharmaceutical analysts, among others.  

The addition of new specialties and the differentiation of old ones is not simply a process of accumulation. As the sapling is not the mature tree in either structure or ecological function, so the 1870 occupational category of chemist is not to be equated with the 75 groupings into which it had been transformed a century later. Nonetheless, certain continuities are obvious. 

In the 1870s most chemists did routine testing for industrial concerns, performing analyses based upon classical gravimetric and volumetric methods. The importance of inorganic chemistry followed naturally from the centrality 

It would be interesting to construct time series of separate subcategories of chemistry as occupation, but figures for the subcategories are not separately reported. 

These two shifts in the complexion of American chemistry — the organic chemists rise to prominence and the growing importance of non-traditional roles for certified chemists - should not obscure the enduring importance of chemical control and testing for industry. New physical methods and more sophisticated apparatus have been added to the chemist s arsenal. However, the analysis of raw materials, intermediate processes, and final products has been a major task of bench chemists throughout 

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