mmm... basic advice is wait and see. I had the same problem with the garden, so I sent one person to water it and left it overnight. The next morning voila! Flowers galore. Somehow I think it helps with the health of the villagers, because they say they feel "well" in it.
Took me about four days to get a master scientist. I just left one person on the table and let them go at it. I had some others comming and going, but had the one guy doing nothing else.