That a stone exhibits now gravity, now rigidity, now electricity, now chemical qualities, depends upon causes, upon impressions upon it from without, and is to be explained from these.
Zergatik harri batek orain pisutasuna, orain solidotasuna, orain elektrizitatea, orain propietate kimikoak erakusten dituen, hori kausen, kanpoko eraginen mendean dago eta horietatik azaldu behar da: