PREFACE. iX 



without this knowledge. I do not mean that you should 

 teach your children all the minute details of these 

 sciences, which would be necessary if you intended 

 them for the practice of medicine and surgery : all I 

 desire is, that the structure of the leading organs of the 

 body should be explained so far as to render the func- 

 tions of them intelligible, and that on this knowledge 

 should be founded a clear and practical elucidation of 

 the laws of health. I can certify, from observation, 

 that this instruction may be communicated to children 

 of ten years of age, and upwards, with great success. 

 The structure addresses their observing faculties, and 

 an explanation of the functions is as interesting to them 

 as a romantic story." 



In treating of physiological subjects, I have unavoid- 

 ably employed some technical terms, but only in cases 

 where there was an evident advantage attending 

 their use; but in all such cases the exact meaning 

 of the term has been assigned it. This explanation 

 saves the necessity of a glossary, which was appended 

 to the first edition, and it is, therefore, omitted in the 

 present. 



It will be perceived that the present edition contains 

 more anatomy than the former. This has arisen from 

 the full conviction, that in order to understand the 

 functions of an organ, its structure must first be learn- 

 ed To aid in the accomplishment of this object, nu- 

 meious well-executed wood cuts have been introduced, 

 alike creditable to the artist and useful to the learner. 



