Final answer:
Henri hopes John will become increasingly resistant to his physical ailments and mental challenges such as nervousness and possibly depression.
Step-by-step explanation:
Henri seems to desire John to become more resistant to illness and weakness. John encourages strong health habits, such as taking cod liver oil, tonics, and consuming nourishing food like ale, wine, and rare meat. He also emphasizes the importance of using one's will and self-control to maintain health, bearing a deep affection for the person he cares for and encouraging them to stay well for both their sake and his own. This focus on health and well-being implies that Henri hopes John will become increasingly resistant to his physical ailments and the mental challenges he faces, perhaps alluding to John's struggles with nervousness and possibly depression, as indicated by mentions of crying when alone and the relentless focus on the wall-paper pattern.