VOLUME 3 The Usefulness of Natural Philosophy and sequels to Spring of the Air, 1662- 3, Introductory Notes A Defence of the Doctrine Touching the Spring and Weight of the Air An Explication of Rarefaction [by Robert Hooke] A Summary of the Contents An Examen of Mr T. Hobbes his Dialogus Physicus De NaturaAeris A Summary of the Contents Some Considerations Touching the Usefulness of Experimental Natural Philosophy. The First Part The Index to the First Part Some Considerations of the Usefulnesse of Naturall Philosophy. The Second Part. The First Section. Of IPs Usefulness to Physick An Appendix to the First Section of the Second Part The Index to the Second Part Glossary