In these and all the other architectural crevices, the Brock Marsh dwellers pursued their trades: physicists; chimerists; biophilosophers and teratologists; chymists; necrochymists; mathematicians; karcists and metallurgists and vodyanoi shamans; and those, like Isaac, whose research did not fit neatly into any of the innumerable categories of theory.
Strange vapours wafted over the roofs. The converging rivers on either side ran sluggishly, and the water steamed here and there as its currents mixed nameless chymicals into potent compounds. The slop from failed experiments, from factories and laboratories and alchymists' dens, mixed randomly into bastard elixirs. In Brock Marsh, the water had unpredictable qualities. Young mudlarks searching the river quag for scrap had been known to step into some discoloured patch of mud and start speaking long-dead languages, or find locusts in their hair, or fade slowly to translucency and disappear.
