ii The Substance of Nature 27 



method yet attempted has been successful in breaking 



up any of these substances into other kinds of matter, 



hence they are called the 



simple substances or ele- ELEMENTS OF THE EARTH'S 



ments. There are about CRUST. 



seventy elements known to 



Oxygen . . . 50-0 

 Silicon . . .25-0 



Aluminium . . 10-0 



Calcium . . . 4-5 



Magnesium . . 3-5 



Sodium and Potassium 3 >6 

 Carbon, Iron, Sulphur, 1 



and Chlorine 



All others 



Total i oo-o 



chemists, but those which 

 have been enumerated, to- 

 gether with carbon, appear 

 to make up by far the greater 

 part of the mass of the Earth. 

 Professor Prestwich gives 

 the accompanying estimate 

 of the proportion in which 

 each of the common elements 

 occur in the Earth's crust. 



46. Transmutation of Elements. For centuries the 

 alchemists firmly believed that one element could be 

 turned into another, and hundreds of men spent their 

 fortunes and their lives in seeking the " Philosopher's 

 Stone" which would bring about the magic change of 

 lead to gold. In more recent times, as the knowledge of 

 the properties of matter has increased, the possibility of 

 such a change has been generally conceded ; but although 

 several modern chemists have believed that they got evidence 

 of transmutation, the fact has never been proved. The re- 

 arrangement of the particles with regard to each other in 

 one kind of matter produces great changes in the outward 

 properties. Charcoal and diamond are simply forms of 

 pure carbon, and each has been changed into the other by 

 the action of energy in certain ways. "Hence it appears 

 possible that the separate elements may themselves be 

 simply different groupings of the one real thing we call 

 matter, associated with different amounts of the other real 

 thing we call energy. 



47. The Periodic Law. Elements are roughly classed 

 into metals and non-metals, but there are intermediate ones 

 which it is not easy to assign to either division. A more 

 natural grouping was discovered by Mr. Newlands in England, 



