PREFACE 



In this book I have sought to place before the general 

 reader a concise, fresh, and plain account of the human 

 body. The circumstances under which it was written 

 serve to explain the nature of its contents. Its chapters 

 represent the substance of a course of lectures I had the 

 honour to give to the audience of boys and girls, men and 

 women, who greet a Christmas lecturer at the Royal Insti- 

 tution. On such an occasion the technical terms used in a 

 medical college are out of place ; the lecturer has to find a 

 way of giving a simple explanation of a machine which is so 

 complex that it needs almost a dictionary of new, and often 

 uncouth, words to name its various parts and workings. 

 Mere simplicity of language, however, will not meet all 

 the difficulties of such a situation. The lecturer must 

 discover and use a fresh machinery for the display of old 

 facts, one which will give opportunities of unveiling, 

 in their proper place and perspective, the more recent 

 advances made by anatomists and physiologists. For that 

 reason 1 went to the workshop of the engineer and 

 selected examples of his inventive ability to illustrate the 

 creative genius displayed by Nature in the construction 

 of the human body. Hence the machinery of our bodies 

 is regarded in this book from a somewhat novel point of 

 view — that of the mechanical engineer. Further, in 

 approaching these lectures I had the feeling that I should 

 weary my audience, as I certainly should my reader, were 



