work by mentioning the titles of some of his books: Observations on Air; The First Principles of Civil Government; Disquisitions relating to Matter and Spirit; On Oratory and Criticism; On the History and Present State of Discoveries Relating to Vision, Light, and Colours; The General History of the Christian Church; the Doctrine of Philosophical Necessity; The Harmony of the Evangelists in Greek; The Rudiments of English Grammar; Experiments on Different Kinds of Air; An Introduction to the Theory and Practice of Perspective; A History of Electricity; The Doctrine of Phlogiston Established (one of his last publications), etc.
With all his faults, sympathies with American and French Revolutionists, heterodoxy, prejudices against antiphlogistians, he was a manly man, devoid of mean acts (which cannot be said of many of his foes), a great worker, brilliant experimentalist, a learned writer, a kind and genial friend, and a great controversialist in the domains of theology, metaphysics, politics, and natural philosophy. He was the father of pneumatic chemistry, but more anon. He never could free himself of the false doctrine of phlogiston; but in the words of Voltaire: "oublions les rêves des grandes hommes et souvenons nous des vérités qu'ils nous ont enseignées."
The truths which Priestley contributed to chemistry have now to be described; but, before doing so, it may
