Final answer:
The quote, "Well, maybe it's not too late. You must give me up. Mind, I haven't changed. I am just the same as ever. I'll see Tull while I'm here, and tell him to his face." proves John Burns tries to belittle Curzon.
Step-by-step explanation:
A quote from the book Forge that proves John Burns tries to belittle Curzon is:
"Well, maybe it's not too late. You must give me up. Mind, I haven't changed. I am just the same as ever. I'll see Tull while I'm here, and tell him to his face."
This quote shows that John Burns is trying to belittle Curzon by implying that Curzon should give him up because he is not worth the friendship and has not changed. It demonstrates John Burns' attempt to diminish Curzon's worth and undermine his relationship with Jane Withersteen.