That's clear, isn't it?
"And now we shift from this particular process to the sum total of all industrial processes in the United States, which includes the leather itself, raw material, transportation, selling, everything.

We will say, for the sake of round figures, that the total production of wealth in the United States is one year is four billion dollars.

Then labor has received in wages, during the same period, two billion dollars.

Four billion dollars has been produced.

How much of this can labor buy back?
Two billions.