In these chapters Marx is concerned with barriers to the speed of value’s circulation. The turnover of capital is the time it takes a capital value to move though production and circulation and reflux back to the capitalist as M’ — though throughout Marx ignores surplus-value: he just wants to show how values move, not how they expand.
As with this volume generally, the question of speeding things up is central. Once we have a value, how can we make it move faster and faster?
These chapters deal particularly with problems arising from the natural forms of commodities’ use-values — both producing them and selling them. The theme of confinement emerges: capital values are either tied-up in production or confined to the form of commodity capital in circulation.