Hence, one of the most essential conditions of a prosperous national economy is that the development of consumption should keep equal pace with that of production, and supply with demand.[215-1] The growth of a nation's economy naturally depends on this: that production should always be, so to speak, one step in advance of consumption, just as the organism of the animal body grows from the fact that the secretions always amount to something less than the amount of additional nutrition. A preponderance of secretions would here be disease; but so would be a too great preponderance of nutrition. Now, the politico-economical disease which is produced by the lagging behind of consumption and by the supply being much in advance of the demand, is called a commercial (market) crisis. Its immediate consequence is, that for a great many commodities produced, no purchasers can be found. The effect of this is naturally to lower prices. The profit of capital and wages diminish. A transition into another branch of production, not overcrowded, is either not possible at all or is attended with care, great difficulties and loss. It is very seldom that all these disadvantages are confined to the one branch in which the disease had its original seat. For, since the resources of the one class of producers have diminished, they cannot purchase as much from others as usual. The most distant members of the politico-economic body may be thereby affected.[215-2] [Footnote 215-1: _Boisguillebert_ lays the greatest weight on the harmony of the different branches of commerce. _L'équilibre l'unique conservateur de l'opulence générale_; this depends on there being always as many sales as purchases. The moment one link in the great chain suffers, all the others sympathise. Hence he opposes all taxation of commodities which would destroy this harmony. (Nature des Richesses, ch. 4, 5, 6; Factum de la France, ch. 4; Tr. des Grains I, 1.) _Canard_ Principes d'E. politique, ch. 6, compares the relation between production and consumption in national economy with that between arteries and veins in the animal body. On the other hand, _Sismondi_, N. Principes I, 381, describes the bewilderment and want which are wont to arise when one wheel of the great politico-economical machine turns round more rapidly than the others.] [Footnote 215-2: Thus, for instance, an occasional stagnation of the cotton factories of Lancashire has frequently the effect of "making all England seem like a sick man twisting and turning on his bed of pain." (_L. Faucher._)] SECTION CCXVI. COMMERCIAL CRISES IN GENERAL.--A GENERAL GLUT.