No single large industry can be depressed without injury to other industries; still less can any great group of industries.

Each industry when prosperous buys and consumes the produce probably of most (certainly of very many) other industries, and if industry A fail and is in difficulty, industries B, and C, and D, which used to sell to it, will not be able to sell that which they had produced in reliance on A's demand, and in future they will stand idle till industry A recovers, because in default of A there will be no one to buy the commodities which they create.

Then as industry B buys of C, D, &c., the adversity of B tells on C, D, &c., and as these buy of E, F, &c., the effect is propagated through the whole alphabet.

And in a certain sense it rebounds.

Z feels the want caused by the diminished custom of A, B, & C, and so it does not earn so much; in consequence, it cannot lay out as much on the produce of A, B, & C, and so these do not earn as much either.