James Marsh
Marsh, James,
1789–1846, English chemist. He is known for his chemical test for arsenic and antimony, called the Marsh testMarsh test,method for the detection of arsenic, so sensitive that it can be used to detect minute amounts of arsenic in foods (the residue of fruit spray) or in stomach contents. The sample is placed in a flask with arsenic-free zinc and sulfuric acid.
..... Click the link for more information. . Using it, very small quantities of arsenic can be detected.