It is good that there is a book for children and young adults about Joseph Priestley. But this one is a bit erratic. It uses contemporary cliches, for instance, "The results of his experiments impacted the way modern scientists...". "impacted" is almost always a bad choice, but it's a very popular one these days. Also, it seems odd that before oxygen had a name, mercuric oxide should have been called mercuric oxide. Because I just read "The Invention of Air", I have been persuaded to take issue with the contention that Priestley discovered oxygen. The author uses first names to identify people fairly frequently, which I find confusing and unnecessarily informal. It describes Priestley's views as liberal, but gives no hint what they were, which is entirely uninformative. It doesn't really explain how his views led to a mob burning down 4 churches and 27 residences. But it is all there is in this category, and some of the quotations are good. ( )