Otto Wallach

As soon as chemists have a definite conception of the internal structure of the molecule of an organic compound, they are able to tackle the task of producing these substances by artificial methods, i.e. by synthesis, as we call it.

In organic chemistry, we have learnt to derive from compounds containing only carbon and hydrogen, i.e. from the hydrocarbons, all other types of combinations, such as alcohols, aldehydes, ketones, acids, etc.