General view of employee Joe Korn operating a boiling tank used in the manufacture of liquid water treatments at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887,…

Close-up view of employee Charles Andrew 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 employee Charles Andrew operating a rolling machine at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company was a…

Close-up view of raw material and machinery used in the manufacture of water treatment chemicals at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn…

General view of employee Walter Perry filling a barrel with an anti-foam water treatment produced at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn…

General view of employee Tom Cryan filling a barrel with water treatment chemicals produced at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in 1887, the Dearborn…

General view of employee Jack Cooney operating a boiling tank used in the manufacture of liquid water treatments at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Founded in…

Close-up view of scientific apparatus used at the Dearborn Chemical Company 35th Street laboratory facilities located in Chicago, Illinois. Founded in 1887, the Dearborn Chemical Company was a corporate ancestor of…

Elevated view of employees Charles S. White (left) and Andrew Lombardi (right) at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Per notations accompanying the…

General view of employees (left to right) Ray Shoan, Charles S. White, Andrew Lombardi, and Bernard Tarley conducting water analysis tests at the Dearborn Chemical Company's 35th Street laboratory and manufacturing…

General view of several employees at work in the Dearborn Chemical Company's 35th Street laboratory and manufacturing facility located in Chicago, Illinois. The three employees visible in the foreground are identified…

General view of two rows of Bunsen burners in use at the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. Per notations accompanying the photograph, the burners are being used to burn…

General view of three Bunsen burners in use at the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. The employee visible in the photograph is identified as Irin Crocker. Founded in…

Close-up view of employee A.R. Sherwood calibrating a concentration hydrometer at the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical Company…

General view of employee James Nelson at work in the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. An assortment of beakers and laboratory apparatus are visible on the work bench.…

Close-up view of employee Irin Crocker using a balance 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 employees A.H. Reynolds and Rea Grimberg at work in the research room at the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. Founded in 1887, the Dearborn Chemical…

General view of employee E.L. Konigsmark recording water samples sent to the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant for analysis. Founded in 1887, the Dearborn Chemical…

Close-up view of employee A.R. Sherwood at work in the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. A row of Bunsen burners are visible on the work bench. Per notations…

General view of employee Ted Slisz at work in the Dearborn Chemical Company's 35th Street Laboratory facility and manufacturing plant. An assortment of beakers is visible on the work bench. Founded in 1887, the Dearborn…

General view of employee Ted Slisz using a balance 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 an unidentified employee analyzing unidentified substances at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. A row of Bunsen burners are visible on the work…

General view of employee Charles S. White analyzing unidentified substances at the Dearborn Chemical Company's 35th Street laboratory facility and manufacturing plant. Assorted scientific apparatus and laboratory…

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 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…