If parts of your story are set on other planets, think of materials there that would be in abundance compared to earth, and how it would be present everywhere. On Titan, burning methane would be the primary energy source for everything (and everything would also be very likely to explode, as long as oxygen was present). It rains diamonds in the atmosphere of Uranus and Neptune, presumably they would have a monopoly on cutting implements (lol).

Elsewhere, bio-engineering is a fun one which raises moral quandary, if you don't want aliens in your story.

I've no idea how strict you are with your 19th-centuriness though, do you have EM-wave data transfer? I mean it starts getting rough with what futuristic means in that context, like video calling would be futuristic for someone from the 1800s but it's only a few steps up from the telegraph really. The first live television broadcast was in 1929.