Chapter XXV

The great merit of an important discovery frequently consists in the first application of some well-known principle of action to a class of objects to which it had not before been applied. When such discovery has been brought before the public in one instance, the application of the same principle to other nearly similar objects requires a much lower degree of inventive talent. A sub-inventor of this sort often views the result of his labour with all the pride of a mother, when he is only entitled to the praise due to an accoucheur.