Vlll PREFACE. 



a reading book, and in part as a class book, 

 in our schools, should smooth or pave the way 

 to the use of those more complete works, the 

 writer would not regret its publication. 



He looks forward to the period as not very 

 distant, whan a knowledge of the physical na- 

 ture of man will be as generally taught to every 

 individual of the whole race as arithmetic and 

 geography now are ; and will be as universally 

 found in our schools. And he cannot but fondly 

 hope to remove a little of the repugnance which 

 many feel to this study, by the peculiar manner 

 in which he has here presented it. 



The general plan of the work is something 

 more than mere theory. It has been tested by 

 experiment, both in school and elsewhere; and 

 with the most complete success. 



There is one more hope that the author in- 

 dulges, in the publication of this volume. It is, 

 that it will have a good tendency on morals. 

 Still more than all this. Besides having the 

 favorable tendency which physiology must have 

 on human happiness generally, the writer be- 

 lieves that no branch of natural science is more 

 likely to induce us to look " through Nature up 

 to Nature's God." 



BOSTON, JANUARY, 1837. 



