Colloid chemistry in North America, 1900-1935. The neglected dimension

This thesis investigates the rise and decline of research interest in colloid chemistry in North America. After a period of high status, colloid research became marginalized despite the efforts of some of North America's most important scientists to promote the study of colloids and organize a national research centre.;In 1861 Thomas Graham classified two types of material by their degree of diffusion through a parchment paper membrane. Material that passed through easily he called 'crystalloids,' and that which passed through slowly or not at all, he named 'colloids.' Graham's work went unexplored until 1900, when a debate developed about the existence of atoms and molecules. Colloids were used to show the kinetic nature of atoms and molecules and demonstrate their existence. In the process, interest was revived in studying colloids.;By 1925 colloids became the focus of intense research. They offered North American scientists the opportunity, despite poor funding and lack of equipment, to contribute to scientific research on a par with European scientists. Besides fundamental research such as that into the existence of atoms, colloids were increasingly important for industry. During World War I, scientists and politicians in North America became concerned about improving science as part of national defense. Colloid chemistry had been important to the war effort, and many chemists had seen the benefits of large scale research and national organization. Following the war, colloid chemists began to organize and planned to establish a national research laboratory. They wanted to place colloid chemistry on an equal footing with physical and organic chemistry.;Despite scientific successes and the utility of colloids, by 1930 the status of colloids was being questioned. Colloid research became associated with outmoded methodology and seemed irrelevant to fundamental scientific questions. Colloid chemistry was also tainted with scandal after the best known American colloid chemist, Wilder Bancroft, presented the American Academy of Sciences with a theory of insanity based on the degree of coagulation of brain cells. His theory was publicly denounced by the AMA as quackery. Colloids eventually became a minor field in physical chemistry, leaving unfulfilled the great expectations of the early period.