292 THE REVIVAL OF INORGANIC CHEMISTRY. 



intelligence not having its seat in a body largely made up of carbon 

 compounds, it might appear somewhat surprising that chemists should 

 have attempted to base a science on the investigation of an element 

 which exists in such relatively insignificant amounts, the compounds 

 of which, with but few exceptions, are incapable of formation at the 

 freezing point of water, or of existence at the lowest red heat, and 

 should have chosen to devote nearly all of their energy to its study. 



Apart from the special subject of coal, petroleum, and asphalt, carbon 

 is of practical importance to the geologist only in the form of carbon 

 dioxide and the carbonates, while of the chemical properties of silicon, 

 which constitutes 27 per cent of the earth's crust, and of the silicates, 

 which make up nearly all of it, we know vastly less than of the deriva- 

 tives of the single carbon compound, benzene. A study of the chem- 

 ical changes taking place in the sun, and of most of those occurring in 

 the interior of the earth, might almost leave carbon out of account; it 

 would certainly have no more importance than titanium, an element 

 of which few but chemists have ever heard, but which is more abund- 

 ant and as widely distributed. 



Carbon, as an essential constituent of living beings, constantly forces 

 itself on our attention, yet this is not to be considered as by any means 

 the chief cause of the predominance of organic chemistry. Compara- 

 tively few of the best-studied organic compounds have more than the 

 remotest connection with the phenomena of life. Phosphorus and 

 sulphur, to say nothing of oxygen, hydrogen, and nitrogen, are quite as 

 important in this respect as carbon, yet how relatively little do we 

 know of phosphorus and sulphur in their chemical relations, or eveu 

 of nitrogen. The extraordinary development of carbon chemistry is 

 due mainly to reasons of a chemical nature, which, by rendering its 

 compounds easier to study, have made progress in this direction a line 

 of least resistance. This has not been without its advantages, for we 

 have been led to discern laws which could not have been perceived so 

 soon had the working forces been more evenly distributed, but it has 

 also had the unfortunate result that the theories of molecular structure, 

 derived wholly from the study of carbon compounds, have been applied 

 to all classes of inorganic compounds too hastily and without sufficient 

 research. The inorganic chemist has done little but make new com- 

 pounds, and ascribe to them structural formulas seldom based on the 

 results of experiment, but rather on the possibility of drawing schemes 

 on paper, in which the various valences or bonds were mutually satis- 

 fied (how, did not matter much), while those substances which were 

 inconsiderate enough to refuse to submit to this operation without vio- 

 lating every probable or possible assumption have been labeled 

 "molecular compounds" and under this name submitted to a forced 

 neglect, which soon resulted in their being forgotten. We shall 

 presently see that an increasing respect for these so-called molecular 

 compounds is one of the features of the revival of inorganic chemistry. 



