Question

Problem 4 In 1860, Robert Burke, John Wills, Charles Gray, John King, and several companions set out from Melbourne, Australia, heading for the Gulf of Carpentaria, in an attempt to be the first to cross Australia from south to north. When they reached Cooper’s Creek, the four men left their companions to wait for them while they continued their trek alone. They were successful in reaching the north coast of Australia, but because of heavy rains they were delayed and ran out of supplies. On their return journey, they began to eat some fresh-water mussels (Velesunio ambiguous) and in a few weeks became sick. Gray soon died. In his journal Wills noted: Our legs almost paralyzed so that each of us found it a most trying task only to walk a few yards. Such a leg bound feeling I never experienced and hope I never shall again. The exertion required to get up a slight piece of rising ground, even without any load, induces an indescribable sensation of pain and helplessness, and the general lassitude makes one unfit for anything. When they reached their camp at Cooper’s Creek, they found that their companions had given up on them and departed. They had, however, left behind a supply of oatmeal and sugar. Adding these to their diet, they recovered almost completely. As they rested at Cooper’s Creek, waiting for a rescue expedition, their oatmeal began to run out and they began to subsist on flour made from the sporocarps of an indigenous fern called nardoo (Marsilea drummondii). This is a popular food among the Australian aborigines. Burke, Willis, and King would grind up the sporocarps and cook them. Soon their symptoms returned. Wills wrote: King out collecting nardoo. I still feel myself, if anything, weaker in the legs, I feel myself altogether too weak and exhausted; the cold plays the deuce with us from the small amount of clothing we have. Mr. Burke suffers greatly from the cold and is getting weak. My pulse are at forty-eight, and very weak, and my legas and arms are nearly skin and bone. Soon Burke and Willis died, with a substantial supply of nardoo flour around them. Shortly thereafter, King was rescued by the aborigines who fed him with nardoo flour until he had partly recovered. The aborigines ate their nardoo flour raw after first soaking it in water. They also drank the water they soaked it in. King never fully recovered; he developed a peripheral neuropathy that made it difficult for him to walk, although he was healthy otherwise. a. Of what did Burke and Willis die? b. What is the toxic substance in nardoo flour and how does it work? c. Why are the aborigines able to subsist successfully on nardoo flour?

Answer 1