The search covered about 2 acres surrounding the pon The investigators noticed that grass surrounding nearby power line poles was wilted and discolored. They specu lated that a herbicide might have been used on the grass A common ingredient in herbicides arsenic in any one of a variety of forms, including arsenic trioxide Sodimm arsenite monosodium methanearsenate and disodium methanearsenate. The last compound is the disodium salt of methane arsenic acid CHAso(OH) which is very soluble in water and thus finds use as the active ingredient in many herbicides. The herbicidal activity of disodium methanearsenate is due to its reactivity with the sulfhydryl (S-H) groups in the amino acid cysteine. When cysteine in plant enzymes reacts with arsenical compounds, the enzyme function is inhibited and the plant eventually dies Unfortunately, similar chemical effects occur in animals as well. The investigators therefore collected samples of the discolored dead grass for testing along with samples from the organs of the deer. They planned to analyze the samples to confirm the presence of arsenic and, if present to determine its concentration in the samples