60 Analyses of Books. [J an". 



The treatise is divided into seven books. The first book is 

 entitled, " Of general Phenomena, and of the Means of making 

 Observations ; " in which, after some remarks upon the nature 

 of matter, the definitions that have been given of it, both phy- 

 sical and metaphysical, we have an account of its essential pro- 

 perties, and the effects necessarily resulting from them. This 

 leads to the method by which these properties are to be ascer- 

 tained, and their amount measured, by means of certain opera- 

 tions, and of peculiar instruments, which are detailed and de- 

 scribed. The titles of the chapters which compose the first 

 uook are as follows : Of the Balance, and the Manner of using 

 it ; of the Construction of the Thermometer, and the Maimer of 

 using it ; of the Destruction and Reproduction of Heat which 

 are observed during the Change in the State of Bodies ; of the 

 atmospherical Pressure, and of the Barometer ; Relations of the 

 Barometer and the Thermometer ; Laws of the Condensation 

 and Dilatation of Air and the Gases, under different Pressures 

 at the same Temperature ; of Pumps, both for Fluids and for 

 Air ; Measure of the Dilatation of solid Bodies, of Gases, and 

 of Liquids, by Heat ; Laws of the Dilatation of Liquids at all 

 Temperatures ; of the Forces which constitute Bodies in the 

 different States of Solids, Liquids, and Gases ; of Vapours in 

 general, particularly of their Formation, and of their elastic 

 Form in a Vacuum ; of the Method of measuring the Weight 

 of Vapours under a given Volume at a determined Pressure and 

 Temperature ; of the Mixture of Vapours with Gases ; of Eva- 

 poration ; of the Hygrometer ; of the Specific Gravity of Bodies ; 

 of the Means of obtaining the Specific Gravity of Bodies ; of 

 Capillary Phenomena ; and of Elasticity. 



The second book is on acoustics, a subject naturally con- 

 nected with the last chapter of the former book, consisting of 

 the peculiar effects which elastic bodies produce on one of the 

 organs of sense. The second book is divided into 13 chapters, 

 under the following titles : of the Production and Propagation 

 of Sound ; of the Perception and Propagation of continued 

 Sounds ; the usual Approximations in Music to express the In-* 

 tervals of Sounds ; Necessity of altering the Adjustment of these 

 Intervals in Instruments with fixed Notes ; Rules for this Tem- 

 perament ; transverse Vibrations of straight elastic Rods ; longi- 

 tudinal Vibrations of straight Rods ; circular Vibrations of 

 straight Rods ; of the Vibrations of curved Rods, such as Forks 

 and Rings ; Vibrations of Bodies rigid or flexible, moved in all 

 their Dimensions ; of wind Instruments ; on the Vibrations of 

 aeriform Fluids different from Air; on the Reverberations of 

 Bodies ; Organs of hearing and speaking. 



Before entering upon the third book, which is on electricity, 

 M. Biot observes, that the properties of bodies about which he 

 has hitherto been treating, are constantly inherent in them, and 

 seem to be essentially attached to the matter of which they are 



