Justine Johnstone in The Plaything of Broadway (1921)

Wikipedia says she was an American stage and silent screen actress, pathologist and expert on syphilis, and that she was part of the team that developed the modern intravenous drip technique.

It goes on to say: When Johnstone’s husband fell ill in 1927, Johnstone became acquainted with his doctor, Samuel Hirschfeld. He convinced her to enroll in some science courses at Columbia University, where she studied plant research. Her work so impressed Harold T. Hyman, head of the science department of Columbia, that he and Hirschfeld hired her to work with them in their research. She joined the staff of the College of Physicians and Surgeons in 1929 as a research assistant in the pharmacology department.

She co-authored a paper with them concerning the development of the modern I.V. unit. Their key breakthrough was to slow down the rate of delivery and avoid what was then known as “speed shock” by introducing the now-ubiquitous drip technique. The three also conducted numerous experiments that led to the cure for syphilis. 

During her time at Columbia, Johnstone co-authored (with a Dr. Blackberg) two other published papers. One dealt with the organization of resuscitation measures; the other, with melnauria. Later, Johnstone and her husband moved to Los Angeles, where as a research assistant to physicians she studied cancer and helped develope the discipline of endocrinology. To aid this research, she installed a laboratory in her house in Hollywood.