The solemn butler knew and welcomed him; he was subjected to no stage of delay, but ushered direct from the door to the dining-room where Dr. Lanyon sat alone over his wine. This was a hearty, healthy, dapper, red-faced gentleman, with a shock of hair prematurely white, and a boisterous and decided manner. At sight of Mr. Utterson, he sprang up from his chair and welcomed him with both hands. The geniality, as was the way of the man, was somewhat theatrical to the eye; but it reposed on genuine feeling. How is Dr. Lanyon characterized in the excerpt?