Marsh Test Apparatus 1867 #2 is a photograph by Science Source which was uploaded on June 5th, 2014.
Marsh Test Apparatus 1867 #2
Marsh Test Apparatus, Steel engraving, 1867. The Marsh test is a method for the detection of minute amounts of arsenic in foods (the residue of fruit... more
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Marsh Test Apparatus 1867 #2
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Science Source
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Photograph
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Marsh Test Apparatus, Steel engraving, 1867. The Marsh test is a method for the detection of 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. Arsine gas (also hydrogen) forms and is led through a drying tube to a hard glass tube in which it is heated. The arsenic is deposited as a "mirror" just beyond the heated area and on any cold surface held in the burning gas emanating from the jet. Antimony gives a similar test, but the deposit is insoluble in sodium hypochlorite, whereas arsenic will dissolve. The test was named for its inventor, the English chemist James Marsh.
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June 5th, 2014