premise: For example , there are persons who are in physical science , in the field of mineralogy , trained in crystallography , who use only X-rays , applying only the powder technique of X-ray diffraction , to clay minerals only , and who have spent the last fifteen years concentrating on the montmorillonites ; or persons in the social sciences in the field of anthropology , studying the lung capacity of seven Andean <mask> .
hypothesis: the proper context for <mask> here should be a member of the race of people living in America when Europeans arrived