I knew that the term 'Snake Oil' (meaning a false-claim, rip off product) came from the wild west where traveling salesmen put on elaborate shows with plants in the audience to demonstrate the near magical powers of their snake oil products.
What I didn't know is that the origins of the miracles of snake oil actually came from something real. Apparently, in Chinese medicine they use the oil from the fatty tissue in water snakes. This is actually very similar to the fish oil supplements people use all the time now. In fact, these snakes contain an even higher percentage of omega-3 fatty acids than salmon (it's one of the things that makes eating salmon so darned healthy) and these omega-3 fatty acids help with digestion, blood pressure, cognitive function and even help ward off depression.
The Chinese railroad workers brought snake oil with them and westerners took note. However, they started using rattlesnakes which do not contain the proper eicosapentaenoic acids and therefor are totally bunk products. And the rest is history.
Read a much more detailed account if you are so inclined at collectorsweekly.com