"'I feel as if I were really beginning to work now,' said Martin. 'This new quinine stuff may prove pretty good. We'll plug along on it for two or three years, and maybe we'll get something permanent—and probably we'll fail!'" (40.4.11)
At the end of the novel, Martin goes to live in a shack in the Vermont wilderness with his buddy Terry so they can do science experiments together. For Martin, the point of life is to pursue scientific truth whether it has any practical value or not—check out the total glee with which he says "…and probably we'll fail!"
He suspects that Terry and he will make no important discoveries, but that doesn't matter to him one bit. All that matters is that they get to wake up each day and work as scientists questing toward Truth.