Canning was a new method of preserving food when the Franklin Expedition set off for the Arctic. It was thought that this new food supply would both sustain the expedition for years (certainly enough time to find the Northwest Passage), and eliminate scurvy.

But the canning process was far from being perfected. In fact, the food may have doomed the expedition.

Firstly, it appears that the lead used to solder the seams of the cans contaminated the food. An analysis of hair samples from bodies found frozen in the ice proved that Franklin's men had lead poisoning. Not only would they have suffered from loss of appetite and weakness, but the lead probably also affected their minds.

Secondly, the food was not cooked properly. This left active bacteria in the cans, and the men likely suffered from a lethal form of food poisoning. Tests done 140 years later showed traces of Clostridium spores (a cause of botulism and tetanus) in a corpse.