Thats not it for sure. He just adds +50% research to the city. It has to have a source of base research for it to do anything.great scientist in your city
I seem to remember reading somewhere in the manual that libraries, universities, markets and banks all add to your science/gold even if you aren't focusing on them (although it may be 2 and 5 not 2 and 4, I don't have it at hand), in addition to multiplying your base rate.