Determinants of commodity prices

The thesis which I humbly submit to criticism is this. If, other things remaining the same, the leading banks of the world were to lower their rate of interest, say 1% below its ordinary level, and keep it so for some years, then the prices of all commodities would rise and rise and rise without any limit whatever; on the contrary, if the leading banks were to raise their rate of interest, say 1% above its normal level, and keep it so for some years, then all prices would fall and fall and fall without any limit except zero