Penicillin nontoxic in humans by first performing toxicity tests in animals and then on humans. His subsequent experiments on penicillin's response to heat and pH allowed Fleming to increase the stability of the compound. The one test that modern scientists would find missing from his work was the test of penicillin on an infected animal, the results of which would likely have sparked great interest in penicillin and sped its development by almost a decade. The importance of his work has been recognized by the placement of an International Historic Chemical Landmark at the Alexander Fleming Laboratory Museum in London on
Valentine S. McClatchy for Mexicans to gain a classification of their race to ensure they would not be able to be exempt from the 1924 Immigration Act. In 1937, he lobbied to strip Kibei, Japanese Americans born in the United States who were sent to Japan to study or visit family for an extended time, of their citizenship if they had been in Japan for more than a year. He died of a heart condition on May 15, 1938. Valentine S. McClatchy Valentine Stuart McClatchy (August 29, 1857 – May 15, 1938) was an American newspaper owner and journalist. As publisher of "The