"The Coming Race", Chapter XI, by Edward Bulwer-Lytton

By "philosophers", the author here means natural philosophers. It's strange he would use this term - today we call such people scientists, as the use of the term natural philosopher predates the advent of modern science, but by the 1870s the use of the term 'scientist' was already widespread, its introduction dating back to 1833. Curious.

Dr. Lewins: Robert Lewins, a 19th century British army surgeon and philosopher. Also: atheist, materialist, and humanist.

I can't find any reference to "ethereal oxygen", other than it was indeed an idea proposed by Dr. Lewins. How odd. It must be elaborated on in some 150 year old book somewhere that just hasn't yet been digitized. What a shame. People always say the entirety of all human knowledge is available at your finger tips with the internet, but clearly that is not the case. A vast amount of human knowledge, yes, but hardly all of it. In fact, given how many obscure remote locales there are with their own local lore and traditions that probably haven't made it into any online format as yet, we're probably not even half way to all human knowledge being on the Internet. Sure, all the current and popular ideas and theories are out there, a lot of what isn't yet online is likely going to obsolete, antiquated, and just wrong, but there's a huge amount that just isn't online at this time. People saying all human knowledge is already online are making quite a value judgment there!

The picture used is "Son Doong Cave, Vietnam" by vtoanstar, used here under the Creative Commons Attribution-ShareAlike 2.0 Generic license (https://creativecommons.org/licenses/by-sa/2.0/).

To follow along: https://www.gutenberg.org/files/1951/1951-h/1951-h.htm#link2HCH0011

Given how short the chapter was, I feel like my reading of it was quite hurried. No idea why. Oops.