Those who are compelled by circumstances to active exertion immediately after a meal, or whose minds are intently occupied in thought or emotion, will find their only safety in eating less than when differently situated. The stomach, having less labour imposed upon it, will require less blood and less nervous energy, and consequently less of both will be abstracted from the other organs which are also in activity, and requiring their assistance. Travellers, literati, and other actively engaged men, know this rule by experience, and some of them have specially noticed its importance. Richard Cumberland, for example, in speaking of his own habits, says: “Nature has given me the hereditary blessing of a constitutional and habitual temperance, that revolts against excess of any sort, and never suffers appetite to load the frame. I am accordingly as fit to resume my book or my pen the instant after my meal as I was in the freshest hours of the morning.”[56] This compatibility of temperate eating with activity did not escape the acute observation of Hippocrates. The state of the mind, indeed, exerts a powerful influence not only on the stomach, but on the whole process of nutrition, and greatly modifies the quantity which may be safely eaten. If the mind be gay and joyous, appetite will be comparatively keen, digestion effective and rapid, and nutrition complete. Examples of this kind abound in childhood, and among an easy-minded well-fed peasantry; whereas if the mind be harassed by care and anxiety, or devoured by grief, envy, jealousy, or other troubles and disquieting passions, the healthy calls of appetite will be scarcely known, and digestion and nutrition will be equally impaired, for it is literally true that “indigestion or, to use the term of the day, a _Bilious attack, as often arises from over exertion or_ ANXIETY OF MIND, as from refractory food.”[57] This fact is exemplified on a large scale in every commercial country, and especially in times of _public distress_ and _political change_. Shakspeare obviously had the principle in view when he made Cæsar exclaim: “Let me have men about me that are _fat_, _Sleek-headed men_, and such as sleep o’ nights. Yond’ Cassius has _a lean and hungry look_; _He thinks too much_: such men are dangerous. _Antony._ Fear him not, Cæsar, he’s not dangerous; He is a noble Roman, and well given.