I skipped writing a bio for Lavoisier. You can read one here, if you're interested. Of note, he is considered by many to be the 'father of chemistry'. After reading part one of 'Elements of Chemistry', it's not hard to see why.
I won't go into great depth here. 'Elements' is very much in the vein of Great Books of basic science and math texts. The usefulness of reading these as a layperson is debatable. I'm of the opinion that if you're really interested in the early days of chemistry, that you're better off reading a history of the period rather than Lavoisier's actual work.
But I don't mean to turn people away from the work. 'Elements' is very readable. It becomes repetitious with experiments, but at least they're easy to follow.
Having said that, there are some things to appreciate. The book opens with Lavoisier explaining why molecular differences change with temperature and how that makes the difference between solids, liquids and gases. He also explains the role that pressure plays in liquid states. It seems obvious once I'd read it, but this was honestly new to me.
It really is amazing the things that Lavoisier did. I was reminded again and again of Lucretius and the poetic atomic theories. Lavoisier actually took various substances and tested and experimented to see what would happen with them. This meant heating and boiling. This meant testing quantities of trapped air. It meant weighing things. And so on and so on.
'Elements' was published so that Lavoisier could get his findings out to other chemists. I'm sure they redid his experiments and compared results. Chemistry was put on a solid footing.