There is no 'royal road' to the amount of the 'apprehension minimum': no abstract argument, and no mathematical computation will teach it to us. And we cannot expect that they should. Credit is an opinion generated by circumstances and varying with those circumstances. The state of credit at any particular time is a matter of fact only to be ascertained like other matters of fact; it can only be known by trial and inquiry. And in the same way, nothing but experience can tell us what amount of 'reserve' will create a diffused confidence; on such a subject there is no way of arriving at a just conclusion except by incessantly watching the public mind, and seeing at each juncture how it is affected. Of course in such a matter the cardinal rule to be observed is, that errors of excess are innocuous but errors of defect are destructive. Too much reserve only means a small loss of profit, but too small a reserve may mean 'ruin.' Credit may be at once shaken, and if some terrifying accident happen to supervene, there may be a run on the Banking department that may be too much for it, as in 1857 and 1866, and may make it unable to pay its way without assistance--as it was in those years. And the observance of this maxim is the more necessary because the 'apprehension minimum' is not always the same. On the contrary, in times when the public has recently seen the Bank of England exposed to remarkable demands, it is likely to expect that such demands may come again. Conspicuous and recent events educate it, so to speak; it expects that much will be demanded when much has of late often been demanded, and that little will be so, when in general but little has been so. A bank like the Bank of England must always, therefore, be on the watch for a rise, if I may so express it, in the apprehension minimum; it must provide an adequate fund not only to allay the misgivings of to-day, but also to allay what may be the still greater misgivings of to-morrow. And the only practical mode of obtaining this object is--to keep the actual reserve always in advance of the minimum 'apprehension' reserve.