604 



SCIENCK 



[N. S. Vol. IX. No. 226. 



derivatives of the single carbon compound, 

 benzene. A study of the chemical 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 abundant and as widely distributed. 

 Carbon, as an essential constituent of 

 living beings, constantly forces itself on 

 our attention, yet this is not to be consid- 

 ered as by any means the chief cause of the 

 predominance of organic chemistry. Com- 

 paratively 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 even of nitrogen. The ex- 

 traordinary development of carbon chem- 

 istry 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 dis- 

 tributed, but it has also had the unfortunate 

 result that the theories of molecular struc- 

 ture, derived wholly from the study of car- 

 bon compounds, have been applied to all 

 classes of inorganic compounds too hastily 

 and without sufficient research. The inor- 

 ganic chemist has done little but make new 

 compounds, and ascribe to them structural 

 formulas seldom based on the results of ex- 

 periment, but rather on the possibility of 

 drawing schemes on paper, in which the 

 various valences or bonds were mutually 

 satisfied (how, did not matter much), while 

 those substances which were inconsiderate 



enough to refuse to submit to this opera- 

 tion without violating 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 re- 

 spect for these so-called molecular com- 

 pounds is one of the features of the revival 

 of inorganic chemistry. 



In the earlier days of chemistry no sharp 

 line was drawn between inorganic and or- 

 ganic substances. It is generally thought 

 that we owe this distinction to Nicholas 

 Lemery, who, in 1675, classified substances, 

 according to their origin, as mineral, vege- 

 table and animal, a distinction which has sur- 

 vived until the present day inpopular speech. 

 Lavoisier, recognizing in substances of 

 vegetable and animal origin the elements 

 carbon, hydrogen, nitrogen and oxygen, 

 and led by his researches to attribute a 

 peculiar importance to oxj'gen, regarded in- 

 organic bases and acids as oxides of simple 

 radicals, and organic bodies as oxides of 

 compound radicals composed of carbon, 

 hydrogen and sometimes nitrogen, but did 

 not otherwise distinguish them. Even in 

 1811 it was undetermined whether carbon 

 compounds obey the laws of constant and 

 multiple proportions, and it was two or 

 three years more before Berzelius, having 

 sufficiently improved the methods of organic 

 analysis, definitely proved that they do, in 

 fact, conform to these laws, but are of greater 

 complexity than the comparatively simple 

 inorganic compounds then known. In his 

 electro- chemical theory, the theory of 

 dualism, developed between 1812 and 1818, 

 Berzelius regarded the simple inorganic 

 bodies, such as the bases and acids, as 

 binary compounds of positive with negative 

 atoms, held together by electrical attraction; 

 the more complex bodies, as the salts, being 

 binary compounds of a higher order; the 

 organic compounds, on the contrary, being 



