PREFACE. 



SINCE 1848, when the " Poetry of Science" was first 

 submitted to the public, two editions have been ex- 

 hausted. This, were proofs required, would of itself 

 show that there is a large circle of readers to whom 

 the deductions of science have an unfailing interest. 

 Beyond this, it conveys an assurance that every truth, 

 however abstract it may appear, has a large popular value 

 if studied in its relations to those generalities which 

 embrace great natural phenomena. With this per- 

 suasion the third edition of the " Poetry of Science" 

 has been extended so as to include all the important 

 discoveries which have been made in Natural Philo- 

 sophy to the end of the year 1853. It is now pre- 

 sented to the world in a new and cheaper form, in the 

 hope, that, with the extension of its circulation, there 

 may be awakened, in still larger circles, a deep and 

 healthful interest in the sciences of which the volume 

 treats. 



K. H. 



Edinburgh, March 7, 1854. 



