The Reading-room was his true home; its warmth enwrapped him kindly; the peculiar odour of its atmosphere—at first a cause of headache—grew dear and delightful to him.
Look at the " it" in " enveloping the tale which brought it out." " It" is the meaning that is brought out by a tale enveloped—everywhere surrounded and enwrapped—by, guess what, the meaning; the meaning is its own membrane.