in 1832, carra came down to canada and the government of new york sends doctors up to up state new york to see what was happening s this thing going to threaten the city of new york and he collected this data that has been mapped. it shows a clear picture, there's cases on hudson river and canal, you can see it coming down, heading straight to new york city, a very clear picture, but nobody in new york want today quarantine the rivers, turn new york into the empire state, this is a huge part of the economy and nobody wanted to close the waterway, which would have been the obvious thing to do, obviously to protect the city at that time. so dr. beck said, well, it might look like callers is coming down the water way but actually it is caused by miasmas, this is 2,000-year-old medical theory that diseases are spread to essentially stinky air, bad smells, that's what they thought bad smells, immigrant, specially the irish in 1832. this was violent, it wasn't they bad mouthed them in the press, there were massacres in the 19th century. [laughter] >> oh, my god. excuse me, let me look at my n