Polar exploration is dangerous... but trudging hundreds of miles in subzero temperatures isn't made any easier if you're suffering from scurvy. The deadly vitamin deficiency destroys the body and will of even the strongest and most determined adventurer - and it seems that scurvy stuck down the ill-fated expedition of Captain Scott. 

But scurvy... in 1912? Hadn't the Royal Navy to which Scott belonged famously cracked the problem of scurvy a century before, with a daily dose of lime juice? How did the 'Limeys' seemingly unlearn that lesson? 

For a full list of sources go to timharford.com