21. [Spraying gas under floor, New York, N.Y.] Publication: [194-?] Subject(s): United States. Public Health Service.
22. [HCN Storeroom, transferring liquid HCN, New York, N.Y.] Publication: [194-?] Subject(s): United States. Public Health Service.
23. [Zyklon poured down a ventilator, cowl removed, New York, N.Y.] Publication: [194-?] Subject(s): United States. Public Health Service.
24. [One safe way of handling a rat, New York, N.Y.] Publication: [194-?] Subject(s): Rodent ControlUnited States. Public Health Service.
25. [Three PHS medical officers in uniform of the early 20th century] Publication: [19--?] Subject(s): United States. Public Health Service.
26. [Men working in a lab, New Orleans, La.] Publication: [between 1914 and 1920] Subject(s): LaboratoriesLaboratory PersonnelUnited States. Public Health Service.
27. [Technician working with a chemical in a dish, New Orleans, La.] Publication: [between 1914 and 1920] Subject(s): LaboratoriesLaboratory PersonnelUnited States. Public Health Service.
28. [USPHS Sanitary Group, New Orleans, La.] Publication: [between 1914 and 1920] Subject(s): Plague -- prevention & controlUnited States. Public Health Service.
29. [U.S. Public Health Service laboratory workers, New Orleans, La.] Publication: [between 1914 and 1920]] Subject(s): Laboratory PersonnelUnited States. Public Health Service.