A symbol from the story is the ego, the super ego, and the id. The ego is the part of your brain that decides what to do and the id and super ego influence it the super ego tells the ego to do the good and the id tells the ego to do the bad. In this story Jekyll is the ego that decides and Hyde is the id that just wants thinks selfishly and Utterson is the super ego that tells Jekyll to do good. This story shows how come people do sometimes what they most want instead of whats right like Jekyll he ended up being taken over by Hyde instead of controlling himself.
Another symbol is how Hyde looks. He is small,ugly,deformed, and hairy how he looks is how he really is. He is all hairy because they want to show him as an animal that only follows his instincts and does what he desires. Many people believed that bad people could be identified by the way they looked that is why Hyde is so ugly and deformed. His size represents that he is a side of Jekyll that had been held back and stopped from growing kind of like a desire that you have in you that you've stop from getting stronger so its small but still there that is why Hyde is short because Jekyll hadn't let him come out before.
Another symbol is the appearance of buildings and places show what is happening there. If it is dark and foggy usually means something bad will happen like Hyde attacking someone. The laboratory in the book is called a certain sinister block of building and is all messed up like Hyde. Jekyll's house in the book is said to have wealth and comfort and look good like Jekyll. Both the lab and house are connected but don't look connected and its hard to notice they look like opposites like Jekyll and Hyde.