During the early 1800’s, early bacteriologists cultivated microorganisms in foods such as potatoes, coagulated eggs whites and various meats.
Bacteria was not easy to cultivate, and gelatin would be used to soldify the petri plate, however, it presented problems
During the same time, Angelina Hesse (also known as Fanny Hesse) and Walther Hesse were a married, German couple, also busy at work, and dedicated to the research and study of microbiology.
My neighbors in New Yrok used Agar-agar for deserts, especially in warmer climates. This might just work!
When Fanny told her husband, he immediately went to Koch. The agar proved to be the perfect substance for microbiological culture, being solid, transparent and sterile. The agar was also thermally stable and resistant to microbial enzymes.
Koch published in 1882 an article about this discovery, but at no time did he name Angelina Hesse in his published body of work, nor did he provide recognition or credit for her contribution.