Sentence:  Attraction, then, is the first phenomenon that arrests our attention, and it is one that is constantly attendant on excitation. It is therefore considered a sure indicator of the presence of <WSD>electricity</WSD> in an active state, and forms the basis of all its tests. 
Meaning of the word marked with <WSD> tags:  Originally, a property of amber and certain other nonconducting substances to attract lightweight material when rubbed, or the cause of this property; now understood to be a phenomenon caused by the distribution and movement of charged subatomic particles and their interaction with the electromagnetic field. (from 17th c.)