Question

why did the Duke give himself up to the sombrae thoughts​

Answer 1

$\huge \sf{ \underline{Answer :-}}$

Suddenly an object rolled before the Duke which he had struck with the toe of his boot; it was a large piece of bread spattered with mud. Then to his amazement, Monsieur de Saulnes saw the Due de Hardimont pick up the piece of bread, wipe it carefully with his handkerchief embroidered with his armorial bearings, and place it on a bench, in full view under the gaslight.

Answer 2

$\huge\underline\mathcal\pink{Answer}$

Because it was a large piece of bread spattered with mud