Close-up view of employee C.M. Hoffman seated at a desk at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor…

General view of female employees at work at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of female employees at work at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of male and female employees at work in an office space at the Dearborn Chemical Company 35th Street laboratory facilities located in Chicago, Illinois. While the majority of the employees are unidentified,…

General view of male and female employees at work at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of assorted water samples sent to the Dearborn Chemical Company's 35th Street Laboratory for analysis. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of BetzDearborn, Incorporated…

General view of employee W. Crocker at work in the factory control work area of the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. Per notations accompanying the photograph,…

General view of an unidentified employee at work in a store room at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant, with view of assorted barrels and other containers. Founded in…

General view of several unidentified employees packing materials for shipment at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company…

General view of two unidentified employees at work in a machine room at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a…

General view of employee Genevieve Work in the Receiving Room at the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. Per notations accompanying the photograph, the Receiving Room was…

General view of an unidentified female laboratory technician preparing a water sample for analysis at the Dearborn Chemical Company's 35th Street Laboratory. Founded in 1887, the Dearborn Chemical Company was a…

General view of several unidentified employees at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor…

General view of an unidentified employee at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of an unidentified employee at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of an unidentified employee at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of several unidentified employees at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor…

General view of two unidentified employees at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

General view of the exterior of the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant, with view of several large storage tanks. Founded in 1887, the Dearborn Chemical Company was a…

General view of the exterior of the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant, with view of several large storage tanks. Founded in 1887, the Dearborn Chemical Company was a…

General view of employees Charles S. White (left) and C.C. Dennis (right) using balances at the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical…

General view of employee C.C. Dennis using a mortar and pestle to crush specimens for use at the Dearborn Chemical Company's 35th Street laboratory and manufacturing facility located in Chicago, Illinois. Founded in…

General view of several unidentified employees at work in the barrel storage area at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical…

General view of several unidentified employees filling barrels at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a corporate…

General view of employee Anton H.R. Noreen preparing samples for testing at the Dearborn Chemical Company's 35th Street laboratory and manufacturing facility located in Chicago, Illinois. Founded in 1887, the Dearborn…