It was what Vernadsky was waiting for. He said, dramatically, “You may hail a modest martyr to science. I tasted the stuff.”
“What?” yelled Novee.
“Just a lick. Don’t worry. I’m the careful-type martyr. Anyway, the stuff is as bitter as strychnine. What do you expect? If a plant is going to fill itself with lead just to keep the animals off, what good does it do the plant to have the animal find out by dying after he’s eaten it? A little bitter stuff in addition acts as a warning. The combination warning and punishment does the trick.”
“Besides,” said Novee, “it wasn’t heavy metal poisoning that killed the settlers. The symptoms aren’t right for it.”
The rest knew the symptoms well enough. Some in lay terms and some in more technical language. Difficult and painful breathing that grew steadily worse. That’s what it amounted to.
Fawkes put down his fork. “Look here, suppose this stuff contains some alkaloid that paralyzes the nerves that control the lung muscles.”
“Rats have lung muscles,” said Vernadsky. “It doesn’t kill them.”
“Maybe it’s a cumulative thing.”
“All right. All right. Any time your breathing gels painful, go back to ship rations and see if you improve. But no fair counting psychosomatics.”
Sheffield grunted, “That’s my job. Don’t worry about it.”