Henry Mathewson, the younger brother of Christy Mathewson, signed with the New York Giants on January 20, 1906. The younger Mathewson did not prove to be as talented as his brother, however, appearing in only two Major League games over the next two seasons for a total of 11 innings and sporting a 4.91 ERA.
Your post led me (eventually) to an enjoyable Christy Matthewson bio at SABR. (http://sabr.org/bioproj/person/f13c56ed). I learned there that tuberculosis cut Henry’s life short at the young age of 30. Of course, Christy himself was felled prematurely, also by tuberculosis and possible exposure to mustard gas during the war. They say that only the good die young, and that was tragically true with the Matthewson brothers.
I knew about Christy Mathewson coming down with tuberculosis, but not Henry! Thanks for that bit of information. Poor guys, what a thing to share.