PEEFAOE 



I HAVE to thank Mr. Knowles of the Nineteenth Cen- 

 tury, Mr. Quilt er of the Universal Review, and the 

 Messrs. Black of the Encyclopaedia Britannica, for 

 permission to include in this volume articles originally 

 published by them. 



The collection which Messrs. Macmillan have 

 kindly undertaken to republish deals with a variety 

 of topics, and is, perhaps, wanting in unity of design. 

 These essays and lectures have, however, all originated 

 in my desire to promote the interests of science, either 

 by explaining some of its later advances to the general 

 public, or by showing the need for increased aid to 

 scientific research from the State. Hence the somewhat 

 comprehensive title which I have ventured to give to 

 this little book. I hope that each paper in its turn 

 may find some readers who will think that it possesses 

 sufficient interest to justify its reappearance in its 

 present form. Some of the papers now reprinted were 

 published sufficiently long ago for changes to have 

 occurred in the position of matters of which they treat. 



