In a certain sense, they only enter into Physics and Chemistry as technological applications.

The reason is that they are too vague.

Where does Cleopatra's Needle begin and where does it end?
Is the soot part of it?
Is it a different object when it sheds a molecule or when its surface enters into chemical combination with the acid of a London fog?
The definiteness and permanence of the Needle is nothing to the possible permanent definiteness of a molecule as conceived by science, and the permanent definiteness of a molecule in its turn yields to that of an electron.

Thus science in its most ultimate formulation of law seeks objects with the most permanent definite simplicity of character and expresses its final laws in terms of them.
Again when we seek definitely to express the relations of events which arise from their spatio-temporal structure, we approximate to simplicity by progressively diminishing the extent (both temporal and spatial) of the events considered.

For example, the event which is the life of the chunk of nature which is the Needle during one minute has to the life of nature within a passing barge during the same minute a very complex spatio-temporal relation.