dephlogisticated air

https://books.google.com/books?id=LhhWAAAAYAAJ&pg=PA387 page 387 As I think I have that ſufficiently proved, the fitneſs of air for reſpiration depends on its capacity to receive the phlogiſton exhaled from the lungs, this ſpecies may not improperly be called, dephlogiſticated air. […] https://books.google.com/books?id=LhhWAAAAYAAJ&pg=PA392 page 392 Upon the whole, I think, it may ſafely be concluded, that the pureſt air is that vvhich contains the leaſt phlogiſton: […] and that there is a regular gradation from dephlogiſticated air, through common air, and phlogiſticated air, down to nitrous air; […]