Second denotes the class to which the first belongs.

Second is the device used by the first.

Second denotes that part of the first, on which the effort is applied.

The production of the first is done by the second.

First is meant for the second.

First is followed by the second.

First is the bigger form of the second

First works for the second.

Second is the constitutional head of the first.

First constitutes the second.