Bud not buddy how is the airnin the library unlike anywhere else?

According to Bud, the smell of the library is different than anywhere else because the air inside of the library appears to be much cooler than the air outside, and the library has a very distinctive smell that is made up of a bunch of other scents that have blended together. Bud noted that scent of leather was easily recognized upon walking into the library due to all of the old books having leather covers.