SCIENTIFIC LITERATURE. 



565 



that they often forget that the study will 

 give them that very knowledge, and that, 

 properly pursued, it is the best possible in- 

 troduction to psychology in general. Every 

 chapter in the present book, he says, is an 

 attempt to organize the knowledge already 

 possessed by those who know little or noth- 

 ing of scientific psychology, and to assist 

 them to inquiries which will give a clearer 

 apprehension of the nature and possibilities 

 of the child. The treatise begins with the 

 wakening of the child to conscious life 

 through the senses, the nature and workings 

 of each of which are described. The bridge 

 over from the physical to the mental is found 

 in consciousness, which for the present pur- 

 pose is denned as the self knowing its own 

 states or activities. The idea of identity and 

 difference arises, symbols are invented or 

 suggested, and language is made possible. 

 The features of language peculiar to children 

 are considered. Muscular or motor control, 

 the feelings, and the will are treated as 

 phases or factors in development, and their 

 functions are denned. The intellect and its 

 various functions are discussed with consid- 

 erable fullness ; and chapters on The Self, 

 Habit, and Character ; Children's Instincts 

 and Plays ; Manners and Morals ; Normals 

 and Abnormals; and Stages of Growth, Fa- 

 tigue Point, etc., follow. A very satisfactory 

 bibliography is appended. 



The Discharge of Electricity through 

 Gases* is an expansion of four lectures 

 given by the author, Prof. J. J. Thomson, of 

 the University of Cambridge, at Princeton 

 University in October, 1896. Some results 

 published between the delivery and printing 

 of the lectures are added. The author begins 

 by noticing the contrast between the variety 

 and complexity of electrical phenomena that 

 occur when matter is present in the field 

 with their simplicity when the ether alone is 

 involved ; thus the idea of a charge of elec- 

 tricity, which is probably in many classes of 

 phenomena the most prominent idea of all, 

 need not arise, and in fact does not arise, so 

 long as we deal with the ether alone. The 

 questions that occur when we consider the 



* The Discharge of Electricity through Gases. 

 Lectures delivered on the occasion of the Sesqir- 

 centennial Celebration of Princeton Univeisity. 

 By J. J. Thomson. New York : Charles Scrib- 

 ner's Sons. Pp. 303. Price, $1. 



relation between matter and the electrical 

 charge carried by it — such as the state of 

 the matter when carrying the charge, and the 

 effect produced on this state when the sign 

 of the charge is changed — are regarded as 

 among the most important in the whole range 

 of physics. The close connection that exists 

 between chemical and electrical phenomena 

 indicates that a knowledge of the relation 

 between matter and electricity would lead to 

 an increase of our knowledge of electricity, 

 and further of that of chemical action, and, 

 indeed, to an extension of the domain of 

 electricity over that of chemistry. For the 

 study of this relation the most promising 

 course is to begin with that between elec- 

 tricity and matter in the gaseous or simpler 

 state; and that is what is undertaken in this 

 book. The subject is presented under the 

 three general headings with numerous sub- 

 headings of The Discharge of Electricity 

 through Gases, Photo Electric Effects, and 

 Cathode Pays. 



For a clear and concise presentation of 

 the framework of psychology and its basal 

 truths, the Story of the Mind* may be com- 

 mended. Although the space afforded is 

 only that of a bird's-eye view, no skeleton 

 bristling with technical terms confronts us, 

 but an attractive and well-furnished struc- 

 ture with glimpses of various divisions that 

 tempt us to further examination. The text 

 is simply and charmingly written, and may 

 induce many to search the recesses of psy- 

 chology who, under a less skillful guide, 

 would be frightened away. A bibliography 

 at the end of the volume supplies what other 

 direction may be needed for more advanced 

 study. Admirable in construction and treat- 

 ment as the book is, there are, however, 

 paths in which we can not follow where 

 Professor Baldwin would lead, and in others 

 that we undertake with him we do not 

 recognize our surroundings as those he de- 

 scribes. This is especially the case with the 

 environment of the genius. We do not 

 find that " he and society agree in regard 

 to the fitness of his thoughts," nor that "for 

 the most part his judgment is at once also 

 the social judgment." If such were the case, 

 how would he " wait for recognition," or be 



* The Story of the Mind. By James Mark 

 Baldwin. New York : D. Appleton and Company. 

 Pp. 23.'. Price, 40 cents. 



