ERSITY BY THE AUTHOR OF CONVERSATIONS ON CHEMISTRY, AND CONVERSATIONS PHILADELPHIA: PUBLISHED AND SOLD BY J. GRIGG, NO. 9, NORTH FOURTH STREET; AND BY 466498 PREFACE. Ir is with increased diffidence that the author offers this little work to the public. The encouraging reception which the Conversations on Chemistry and Political Economy have met with, has induced her to venture on publishing a short course on Natural Philosophy; but not without the greatest apprehensions for its success. Her ignorance of mathematics, and the imperfect knowledge of natural philosophy which that disadvantage necessarily implies, renders her fully sensible of her incompetency to treat the subject in any other way than in the form of a familiar explanation of the first elements, for the use of very young pupils. It is the hope of having done this in a manner that may engage their attention, which encourages her to offer them these additional lessons. They are intended, in a course of elementary science, to precede the Conversations on Chemistry; and were actually written previous to either of her former publications. CONTENTS. Page. INTRODUCTION.-General Properties of Bodies.-Impenetrability.- Extension.-Figure.-Divisibility.-Inertia.-Attraction.--Attrac tion of Cohesion.-Density.-Rarity.—Heat.-Attraction of Gravi- Attraction of Gravitation, continued.-Of Weight.-Of the Fall of Bodies. Of the resistance of the Air.-Of the Ascent of Light Of Motion.-Of the Inertia of Bodies.-Of Force to Produce Motion. -Direction of Motion.-Velocity, absolute and relative.-Uniform Motion, Retarded Motion.-Accelerated Motion.-Velocity of Falling Bodies.-Momentum.-Action and Reaction Equal.-Elas- ticity of Bodies.—Porosity of Bodies.—Reflected Motion.—Angles |