A HARD-WORKING DIET. 333 



words in reference to the starting of trains, or that a 

 horse's "price at starting" would have no reference 

 to the cost at which it could be purchased even in a 

 " selling stakes " race. 



If you want to explain to the first man you meet, 

 so that it may be of any practical use to him in the 

 arrangement of his daily diet, what is the present way 

 of regarding the relative use of fish as compared 

 with other foods, you must make sure that there is 

 a mutual understanding between your hearer and 

 yourself about the sense in which you use such words 

 as "work," "force," "burn," " element," " oxidise," and 

 that he knows what you mean when you use such 

 words as Carbon, Hydrogen, Oxygen, and Nitrogen. 

 Your listener would very probably tell you he 

 could not follow you, as he was not familiar with 

 your words and terms, and had no idea what they 

 meant. You might by degrees find out you had 

 to give him very rudimentary information before 

 he could follow you at all. 



At the outset, a misunderstanding would very The sense in 

 probably occur about the use of the words "element " wor ds "de- 



and "compound." The old alchemists meant b 



" the elements " Earth, Air, Fire and Water, and the are used - 



term still lingers in our language. It is not uncommon 



to meet with the expression "the raging of the 



elements " in a description of a thunder-storm, and, in' 



an account of a large fire, " the all-devouring element " 



is pretty sure to be mentioned. The modern chemist, 



however, uses the word " element " only in contrast to 



" compound." A compound can be split up into two, 



and, in many cases, three or more essentially different 



materials, as, for example, brass can be split up into 



