972 Organic Compounds in tkeir Relations to Life. [December, 



nominal, and the existence of any hard and fast line marking off 

 one of these fields from the other has long been denied. If there 

 were any advantage to be derived from such a line perhaps it 

 could not be drawn in a better place than that where carbon 

 unites with hydrogen or nitrogen, either with or without oxygen. 

 This, it is true, would place all the hydrocarbons, as well as cyan- 

 ogen in the organic series. On this view, therefore, the inorganic 

 compound most nearly related to the organic series would be car- 

 bonic acid, or, as it is now more properly called, carbonic dioxide, 

 C0 2 , of whose inorganic origin there can be no doubt. The 

 simplest organic compounds consist chiefly in the addition of 

 different proportions of hydrogen to this basis and the reduction 

 of the proportion of oxygen. In the various hydrides (methylic, 

 CH 4 , ethylic, CH (i . amylic, C 5 H 12 , etc.), the oxygen disappears 

 altogether. In the alcohols it reappears only in the addition 

 of one oxygen molecule, to the respective hydrides. The 

 acids result from an additional increase in the proportion of oxy- 

 gen (formic, CH 2 2 , acetic, C,H 4 0.>, etc.). The actual devel- 

 opment of the organic compounds, as it maybe supposed to take 

 place in nature, would seem to be in the reverse order to that 

 above given, the organic acids being first formed from inorganic 

 compounds by the addition of hydrogen, then the alcohols from 

 these by still further increase of hydrogen accompanied by a re- 

 duction of oxygen, and lastly, the hydrides from the alcohols by 

 the loss of the one equivalent of oxygen remaining in the latter. 

 The different kinds of acids, alcohols, and hydrides, arise from 

 varying the proportions of hydrogen and carbon. The simplest 

 change possible may be indicated thus : 



When we look at the higher and more complex compounds, 

 e can readily see that they may be composed of the lower ones 

 ^ their molecular constituents. This is, to a great extent, 

 ssumed by chemists, and the chemical synthesis of a large nurn- 



