First things first. He had to earn a living. To do so, he had to find out about poisons and antidotes. He moved into the apartment in back of his store and began reading the books left by the late Hadji Draken. The literature on poisons was fascinating. There were the vegetable poisons known on Earth, such as hellebore, setterwort, deadly nightshade, and the yew tree. He learned about the action of hemlock--its preliminary intoxication and its final convulsions. There was prussic acid poisoning from almonds and digitalin poisoning from purple foxglove. There was the awesome efficiency of wolfsbane with its deadly store of aconite. There were the fungi such as the amanita toadstools and fly agaric, not to mention the purely Omegan vegetable poisons like redcup, flowering lily, and amortalis. But the vegetable poisons, although dismayingly numerous, were only one part of his studies. He had to consider the animals of Earth, sea, and air, the several species of deadly spiders, the snakes, scorpions, and giant wasps. There was an imposing array of metallic poisons such as arsenic, mercury, and bismuth. There were the commoner corrosives--nitric, hydrochloric, phosphoric, and sulphuric acid. And there were the poisons distilled or extracted from various sources, among which were strychnine, formic acid, hyoscyamine, and belladonna. Each of the poisons had one or more antidotes listed; but those complicated, cautiously worded formulas, Barrent suspected, were frequently unsuccessful. To make matters more difficult, the efficacy of an antidote seemed to depend upon a correct diagnosis of the poisoning agent. And too often the symptoms produced by one poison resembled those of another. Barrent pondered these problems while he studied his books. In the meantime, with considerable nervousness, he served his first customers. He found that many of his fears were ungrounded. In spite of the dozens of lethal substances recommended by the Poison Institute, most poisoners stuck single-mindedly to arsenic or strychnine. They were cheap, sure, and very painful. Prussic acid had a readily discernible odor, mercury was difficult to introduce into the system, and the corrosives, although gratifyingly spectacular, were dangerous to the user. Wolfsbane and fly agaric were excellent, of course; deadly nightshade could not be discounted, and the amanita toadstool had its own macabre charm. But these were the poisons of an older, more leisurely age. The impatient younger generation--and especially the women, who made up nearly 90 per cent of the poisoners on Omega--were satisfied with plain arsenic or strychnine, as the occasion and opportunity demanded.