How did Dantes realise that Faria was about to die?

In "The Count of Monte Cristo" by Alexandre Dumas, Dantes realizes that Faria is about to die through a series of events:

1. Faria's Health Deteriorates: Faria, who was already old and frail, begins to suffer from a series of seizures and his health rapidly deteriorates. This is the first sign to Dantes that Faria may not have much time left.

2. Faria's Paralysis: After one particularly severe seizure, Faria becomes paralyzed on one side of his body. This further indicates to Dantes that Faria's condition is worsening and that he may be nearing the end of his life.

3. Faria's Confession: As his health continues to decline, Faria decides to share his secret with Dantes - the location of a hidden treasure on the island of Monte Cristo. This confession suggests to Dantes that Faria is preparing for his death.

4. Faria's Final Words: Just before he dies, Faria blesses Dantes and tells him to use the treasure wisely. This final act confirms to Dantes that Faria knew he was about to die.

In summary, Dantes realizes that Faria is about to die through a combination of Faria's deteriorating health, his paralysis, his confession about the treasure, and his final words.