7i AMERICAN PREFACE. 



It is designed to consist of compendious scientific trea- 

 tises, representing the latest advances of thought upon sub- 

 jects of general interest, theoretical and practical, to all 

 classes of readers. The familiar phenomena of surrounding 

 Nature, in their physical and chemical aspects, the knowledge 

 of which has recently undergone marked extension or revision, 

 will be considered in their latest interpretations. Biology, or 

 the general science of life, which has lately come into promi- 

 nence, will be explained in its leading and most important 

 principles. The subject of mind, w 7 hich, under the inductive 

 method and on the basis of its physical accompaniments and 

 conditions, is giving rise to a new psychology, will be treated 

 with the fulness to winch it is entitled. The laws of man's 

 social development, or the natural history of society, which 

 are now being studied by the scientific method, will also re- 

 ceive a due share of attention. While the books of this 

 series are to deal with a wide diversity of topics, it w r ill be a 

 leading object of the enterprise to present the bearings of 

 inquiry upon the higher questions of the time, and to throw 

 the latest light of science upon the phenomena of human 

 nature and the economy of human life. 



As the first requisite of such a series of works is trust- 

 worthiness, their preparation has been confided only to men 

 of eminent ability, and who are recognized authorities in 

 their several departments. As they are to address the non- 

 scientific public, it is a further requisite that they should be 

 written in familiar and intelligible language. It is not to be 

 expected that the authors will all attain to the same stand- 

 ard in this respect, but they are pledged to the utmost sim- 



