Answer: When the author mentions the "huge city" with "stores of heaped-up wealth", he means that in urban agglomerations where the rush of city life is so heavy and the persuit of weath seems to be the order of the day, the perception of time is almost lost in chaos. The clear image of this is Jurgis visiting the doctor and realising he had become an old man almost without realising it. Now he has no work and the normal aches and pains that come with age. At this point, he feels he was "used" by others when they had the chance to take advantage of him but now that he can't put up with the crazy speed of life, he's just discarded, thrown away; and that gives him a bitter taste in his mouth.