Hand-colored lithograph with examples of the 24 botanical taxonomic classes: Monandria, Diandria, Triandria, Tetrandria, Pentandria, Hexandria, Heptandria, Octandria, Enneandria, Decandria, Dodecandria, Icosandria,…

Hand-colored lithograph of spring crocus, Crocus vernus. Class Triandria, order Monogynia.

Hand-colored lithograph of common holly, Ilex aquifolium. Class Tetrandria, order Tetragynia.

Hand-colored lithograph illustrating the parts of a flower, using the example of the common wallflower. Included parts are the flower, cup, corolla or blossom, stamen, pistil, seed-vessel, and receptacle.

Hand-colored lithograph of water mouse ear, Myosotis palustris, now known as the water forget-me-not. Class Pentandria, order Monogynia.

Hand-colored lithograph of germander speedwell, Veronica chamaedrys. Class Diandria, order Monogynia.

Los Angeles County General Hospital nurse Mary Finlay is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions,…

This nurse is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions, but until the 1950s doctors did not realize…

This nurse is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions, but until the 1950s doctors did not realize…

Los Angeles County General Hospital nurse Mary Finlay is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions,…

Photograph depicting male and female chemistry students in a laboratory at an unidentified school or college. The students are grouped around several laboratory stations and are seen using test tubes and Bunsen burners…

Group photograph depicting members of the chemistry club at Wilson College in Chambersburg, Pennsylvania. The group consists of nine women gathered around a table while observing one member pouring an unknown substance…

Photograph depicting a group of male and female chemistry students at an unknown school or college. The students are posed holding assorted laboratory equipment and glassware. Some of the female students are also…

Color photograph of Eleanor Vadala, Chemist, and C.A. Cassola, Division Superintendent, working with a barrel of radioactive material at the Naval Air Material Center's Aeronautical Materials Laboratory. Ms. Vadala…

Eleanor Vadala, chemist, demonstrating use of the Gammacell 220, a textile chemistry machine, at the Naval Air Material Center's Aerospace Materials Laboratory. The Gammacell 220 is a source of Cobalt-60 gamma…

Eleanor Vadala, chemist, and Dr. Earl Hayes, U.S. Defense Department, examining a display of airship fabric produced at the Naval Air Material Center. Ms. Vadala demonstrates the threads on an airship model while Dr.…

Laboratory staff in the High Polymer Division of the Naval Air Engineering Center's Aeromaterials Laboratory examining the first batches of new NARPOL polymers used to coat aircraft metals. The individuals in the…

Award ceremony in honor of Sally J. Ketcham, Metallurgist at the Naval Air Engineering Center located in Johnsville, Pennsylvania. The individuals in the photograph are identified as follows (from left): J. Hartley…

Black and white photograph of a Beckman Instruments employee modeling the use of a syringe to inject a sample into a Model E Ultracentrifuge vial.

Beckman Instruments began producing centrifuges after its January 1,…

Women employees and technicians assemble Helipot products at benches. The Helipot Division of Beckman Instruments mostly produced potentiometers and other electrical components.

Potentiometers regulate the flow of…

Women employees and technicians assemble Helipot products at benches. The Helipot Division of Beckman Instruments mostly produced potentiometers and other electrical components.

Potentiometers regulate the flow of…

This oxygen analyzer is being used to ensure food safety by measuring the oxygen content of the headspace inside food packaging. Oxygen readings that are too high could indicate an environment that encourages the growth…

Letter from Irène Joliot-Curie (1897-1956) to Raymond Delaby (1891-1958), general-secretary of the International Union of Pure and Applied Chemistry (IUPAC) concerning the appointment of Norwegian radiochemist Ellen…

Letter from Marie Curie (1867-1934) to Einar Biilman, President of the International Union of Pure and Applied Chemistry (IUPAC) concerning an invitation to serve on IUPAC's Commission on Atomic Weights. Curie expresses…

This transistorized data processor was made for Aerojet Corporation in the early 1960s. It was produced by Beckman Instruments' Systems Division, which made (among other things) aerospace industry instruments like these…