it appears to the reader (when nancy is describing monks in ch.46) that mr. brown appears to know him use textual evidence that demonstrates

It is evident that Mr. Brownlow recognizes Monks when he hears Nancy's description.

"Part of this," said the girl, "I've drawn out from other people at the house I tell you of, for I have only seen him twice, and both times he was covered up in a large cloak. I think that's all I can give you to know him by. Stay though," she added. "Upon his throat: so high that you can see a part of it below his neckerchief when he turns his face: there is-"

"A broad red mark, like a burn or scald?" cried the gentleman.

"How's this?" said the girl. "You know him!"

The young lady uttered a cry of surprise, and for a few moments they were so still that the listener could distinctly hear them breathe.

"I think I do," said the gentleman, breaking silence. "I should by your description. We shall see. Many people are singularly like each other. It may not be the same."