Upon finding out that his gold was missing, Silas had a series of reactions that became a chain of events which led to Silas's ultimate breakdown. Interestingly, this horrible moment was also the beginning of Silas's new outlook in life.
When Silas entered his cottage and found the gold missing, he first looked around in anxiety trying to figure out where it was. Then, he looked outside his cottage to see if he could figure out more. Then he cried a loud shriek after he looked for the gold everywhere he could think of.
According to the text:
Again he put his trembling hands to his head, and gave a wild ringing scream, the cry of desolation. For a few moments after, he stood motionless; but the cry had relieved him from the first maddening pressure of the truth. He turned, and tottered towards his loom, and got into the seat where he worked, instinctively seeking this as the strongest assurance of reality.
After this first reaction, Silas left his house in despair, wondering about the streets on his way to The Rainbow, and it was there where Silas basically entered and, in summary, lost his mind.
This was the first time that the people of Raveloe felt compassion for Silas, and they even took it upon themselves to ensure Silas's recovery. Like stated before, this was the beginning of Silas's transformation. Losing it all meant gaining a new view of life.