THE REVIVAL OF INORGANIC CHEMISTRY. 291 



erties, many of which can only be obtained by work which is so elabo- 

 rate and difficult, and which requires such concentration of effort, that 

 he who follows it can well be excused if he does not always look on the 

 product of his labor as merely means to another end. It is tolerably 

 clear that, for a long time to come, experiinentizing must keep equal pace 

 with inathematizing, and if the former have been pushed so far in one 

 direction as to appear to afford no prospect of continued progress we 

 must not abandon it altogether, but consider whether it may not be 

 still profitably pursued along other lines. Let us consider whether we 

 must all turn mathematical chemists, or whether there is not much left 

 to be done by those trained in the older school, working along old- 

 fashioned lines and by old-fashioned methods. 



Descriptive chemistry, as it exists to-day, is a science which has 

 grown and is still growing enormously in a single direction, that of 

 organic chemistry, the chemistry of the compounds of carbon. We are 

 at present acquainted with about seventy-five chemical elements, which 

 are found in the most varied proportions in those parts of the earth 

 which are accessible to our observation, namely, the crust, the sea, and 

 the air. The accompanying table, calculated by Clarke, shows the rel- 

 ative abundance of the elements in a sphere comprising the crust for a 

 depth of 10 miles, the ocean, and the atmosphere : 



Oxygen 49. 98 



Silicon 25. 30 



Aluminium 7. 26 



Iron 5.08 



Calcium ... 3.51 



Magnesium 2. 50 



Sodium 2.28 



Potassium 2. 23 



Hydrogen 94 



Titanium '. 30 



Carbon 21 



Chlorine } ri 



Bromine ) 



Phosphorus ■ 09 



Manganese 07 



Sulphur 04 



Barium , .03 



Nitrogen 02 



Chromium 01 



The nineteen elements here given make up nearly the whole mass; 

 the remaining fifty-five or thereabouts, taken together, and making all 

 possible allowance for error, do not amount to more than 1 per cent. 

 Observe that the element carbon amounts to but one-fifth of one per 

 cent. To be snre, this is no argument that the chemistry of carbon is • 

 relatively unimportant; on the contrary, there is no necessary connec- 

 tion between the abundance of an element and its ability to carry us 

 further toward a knowledge of chemical laws. Nevertheless, to an 



