A melancholy chapter. We find out (after the fact) how the last part of the battle goes. Bilbo mentions how victory seems to be a dreary affair, and we heard him say last chapter that he had heard defeat could be glorious but it seemed to be only tragic, and taken together this amounts to "battles aren't cool". Which is, of course, a Hobbit's take on things, but probably also JRRT's, since if there was ever a war to sour you on the idea of war it would be World War 1, which he fought in as a young man.
Lots of tearful goodbyes, and Thorin in particular manages to go out on a good note. We find out that Gandalf, whose arm is in a sling, can be injured by something less powerful than a balrog, presumably a goblin. We find out that Fili and Kili died, but the rest of the 13 dwarves survived, which amounts to a morbidity rate of 22% or so, pretty high for the victorious side in a single battle. It is also mentioned that the wood-elves who died could have been living for millenia more, partying in the forest, which makes the idea of dying in combat against goblins even more sad.
Then, Bilbo ends up leaving with "only" a small chest of gold and silver, and a necklace which he ends up giving to the Elvenking at their parting. In both of these, he shows an apparent resistance to the "dragon-sickness" that afflicts the Master of Laketown, Thorin, and so many others who get excessively greedy at the thought of all that treasure. The Elvenking names him "elf-friend", which at the time seems just a nice gesture but in Lord of the Rings we start to get the idea that this fact is somehow visible to other elves; no hint of this in The Hobbit, though.
One wonders what it was like travelling with Gandalf and Beorn all that way. The last half of this chapter is gradually travelling back from the pre-medieval sounding Lonely Mountain, to the early medieval, Beowulf-era Beorn's House, and then through the Misty Mountains, heading back towards Bilbo's Edwardian home in the Shire. But, not there yet.
Chapter 19