48 Microbes and You 



means very gelatmous) as a solidifying agent in her own jelly and 

 jam recipes at home. She picked up this technic from her mother, 

 who in turn received it from some Dutch friends who had lived 

 in Java. In the East Indies agar-agar had been employed for 

 generations as a thickening agent for both soups and jellies. Why 

 not try agar-agar in place of gelatin, she suggested to her husband. 

 An historic moment in microbiology was reached by this simple, 

 yet necessary, substitution. An occasional contribution of an un- 

 known individual can make discoveries of lasting value. Oliver 

 Wendell Holmes (1809-1894) stated that medicine learned "from 

 a Jesuit how to cure agues, from a friar how to cut for the stone, 

 from a soldier how to treat gout, from a sailor how to keep oflF 

 scurvy, from a postmaster how to sound the eustachian tube, from 

 a dairymaid how to prevent smallpox, and from an old market 

 woman how to catch the itch-insect." To this imposing list we 

 can add a housewife who helped her husband solve the perplexing 

 problem of pure culture isolation technics. Without delay this 

 new substance derived from Japanese seaweed ( Gelidium corneum ) 

 was reported to Koch, probably in the latter half of 1881. Koch 

 adopted it and in his famous publication of 1882 in which he 

 announced his preliminary investigation on the tubercle organism 

 (Mijcohacterium tuberculosis), he made reference to agar-agar in 

 one brief sentence. Fanny Hesse, who had been born in 1850 

 in New Jersey in the present locality of Jersey Cits^, died in 1934, 

 with few bacteriologists realizing that the credit often ascribed to 

 Koch originated with her suggestion to her research-minded 

 husband. 



When our source of agar was cut off during World War II, the 

 United States was obliged to seek a new supply. After some 

 intensive searching, beds of the species GeUdeum cartUagineum 

 were discovered off the coast of California, and much of our war- 

 time agar came from this source. 



By perfecting new technics and by making use of this new- 

 found agar base for his culture media, Koch began a long series 

 of fruitful discoveries, complementing much of the work of his 

 French colleague in microbiology, Louis Pasteur. Koch proved 



