The book "Investigations Chemical and Philosophical; Chiefly Concerning Nitric Oxide or Deflogisticated Nitric Oxides and Its Breathing" by Sir Humphrey Davy is an outstanding scholarly work devoted to the study of nitrous oxide, also known as dephlogisticated nitrous oxide, and its effects on the body. In this book, the author talks about his experiments with this substance, as well as the results of studying its effect on breathing. This work played an important role in the development of chemistry and medicine, and still remains a source of important scientific information.