The quote appears to be cited in the following article. Though it is likely they source it from the Brown book, it might be worth taking a look at if you can to a library that holds it, or request a copy of the article through interlibrary loan.

"Land Speculation and the Taxing Power"
J. Rupert Mason
American Journal of Economics and Sociology, Vol. 7, No. 4 (Jul., 1948), pp. 487-492

You can use WorldCat to find it in a library near you.