It was the best of times it was the worst of times; the building boom of the Northeast never stooped really from 1850-1930 the demand for stone gobbled up al the available local stone....The best were the tight grain blue grays out of places like Belleville New Jersey.....the weaker ones were coarse grain red browns from Pensa to Maine ...the demand was so great that little care was taken about the bedding planes when quarried after all only the stonemason and the contractor could read these planes and they all knew any problems with it would be in 100 yrs. Later and if I can be so brief without much of a defense here we are ...peeling away layers turning to dust. Ok .stop the water first........call Mike Edison second and send him a sample to make a custom patch mix ..or find the quarry your brownstone came from and cut new stone ...most salts willl come off in hot water low psi 200 deg F rince....lastly you can consolidate the historic original but thats affected by UV and might not be worth it...Good luck see you in 10 days Michael -- To terminate puerile preservation prattling among pals and the uncoffee-ed, or to change your settings, go to: <http://maelstrom.stjohns.edu/archives/bullamanka-pinheads.html>