Tamoszius Kuszleika is a gifted violinist. His skills mean that he could make lots of money. But unfortunately (from a practical perspective), he falls in love with Marija Berczynskas. When Marija falls into financial trouble, Tamoszius keeps loaning her more and more money. He depletes his savings out of love for Marija. Then, while Jurgis is off on the road and Marija decides she has no choice but to become a prostitute, Tamoszius gets a hand injury that results in amputation. He can no longer play the violin, and Marija never sees him again.
For Sinclair, Tamoszius's story has a specific message: not only does business competition ruin relationships, but it also apparently destroys art (Tamoszius is a genius on the violin). Still, the demands of his family life (i.e., Marija) and his manual labor destroy his ability to play. We can compare Tamoszius's tragic fate with the ideal future socialist world of Dr. Schliemann's dreams, when he promises that after the revolution, all artistic activity will be supported by associations for artists, musicians, writers, or what have you. No one will have to work himself to death to play the violin in Dr. Schliemann's socialist heaven.