Rosa Luxemburg,
The Accumulation of Capital
“ The constant capital which has been spent by the two departments is in reality only part of the constant capital used by society. This constant capital is divided into two parts; the first is fixed capital—premises, tools, labouring cattle—which functions in a number of periods of production, in every one of which, however, only part of its value is absorbed by the product, according to the amount of its wear and tear. ”
