MANUAL FOR SUGAR GROWERS. 3 



be created or destroyed, nor can the elements be 

 changed one into the other ; potassium is always 

 potassium, nitrogen always nitrogen, and so on, 

 though the substances which can be obtained by 

 combining these elements in various ways are end- 

 less in number. 



For the sake of convenience it is customary to 

 represent each element by means of a symbol, usu- 

 ally the first letter of its name, and this symbol also 

 indicates a definite quantity of the element, the 

 equivalent or combining weight. Thus the symbol 

 C indicates carbon, but it also stands for twelve parts 

 by Aveight of carbon. (See equivalent weights in 

 table.) Again, the symbols H and O stand for one 

 part by weight of hydrogen and sixteen of oxygen 

 respectively. Compounds are formed by the union 

 of two or more elements and are represented sym- 

 bolically by writing the symbols of the constituent 

 elements together, the quantity of any particular 

 element present in a compound being indicated by 

 a small figure placed a little below and to the right 

 of the element in question : thus, water is found by 

 experiment to be composed of the elements oxygen 

 and hydrogen, and also to contain two parts by 

 weight of hydrogen to sixteen parts by weight of 

 oxygen. These facts are represented by the sym- 

 bol H,0.- 



* For a full explanation of tliis subject any good elementary 

 text-book should be consulted, this outline being merely given 

 in order that the chemical formulae, etc., necessarily employed 

 may be to some extent understood by those having no chemical 

 knowledge. 



