Robert Boyle

Robert Boyle: A Free Enquiry into the Vulgarly Received Notion of Nature: A Free Enquiry into the Vulgarly Received Notion of Nature

Acknowledgements List of abbreviations Introduction Chronology A note on the text A Free Enquiry into the Vulgarly Received Notion of Nature The Preface Section I Section II Section III Section IV Section V Section VI Section VII Section VIII Glossary Index.

The Spring of the Air

A qualitative atomic theory of the “spring” of the air—i.e. its property of resisting compression by exerting pressure on a surface in contact with it—is proposed. Boyle conceives the air to be similar to “a heap of little bodies, lying one upon another, as may be resembled to a fleece of wool”. Each body is like a little spring, which can be easily bent or rolled up, but also tries to stretch itself out again. This tendency to expand is characteristic not only of air that has been compressed, but also of the ordinary air in the atmosphere, which has to support the weight of a column of air many miles in height above it. In support of this theory, the experiment of Pascal is mentioned, in which it was shown that the height of mercury in a barometer is less at the top of a mountain than at the bottom. (Boyle assumes that the mercury is supported by air pressure rather than by natures abhorrence of a vacuum.)