REQUISITE AMOUNT OF FOOD. 489 



sense of satiety, is the proper guide. " There appears to be a sense of per- 

 fect intelligence conveyed to the encephalic centre, which, in health, invariably 

 dictates what quantity of aliment (responding to the sense of hunger and its 

 due satisfaction) is naturally required for the purposes of life ; and which, if 

 noticed and properly attended to, would prove the most salutary monitor of 

 health, and effectual preventive of disease. It is not the sense of satiety, 

 for this is beyond the point of healthful indulgence, and is Nature's earliest 

 indication of an abuse and overburden of her powers to replenish the system. 

 It occurs immediately previous to this ; and may be known by the pleasurable 

 sensations of perfect satisfaction, ease and quiescence of body and mind. It 

 is when the stomach says, enough ; and it is distinguished from satiety by 

 the difference of sensations, the latter saying too much.' 1 '' Every medical 

 man is well aware how generally this rule is transgressed ; some persons 

 making a regular practice of eating to repletion ; and others paying far too 

 little attention to the preliminary operations, and thus ingesting more than is 

 good for them, even though they may actually leave off with an appetite. 



650. Although no universal law can be laid down for individuals, however, 

 it is a matter of much practical importance to be able to form a correct ave- 

 rage estimate. It is from the experience afforded by the usual consumption 

 of food by large bodies of men, that our data are obtained ; and these data 

 are sufficient to enable us to predict with tolerable accuracy what will be re- 

 quired by similar aggregations, though they can afford no guide to the con- 

 sumption of individuals. We shall first consider the quantity sufficient for 

 men in regular active exercise ; and then inquire how far that may be safely 

 reduced for those who lead a more sedentary life. The Diet-scale of the 

 British Navy may be advantageously taken as a specimen of what is required 

 for the first class. It is well known that an extraordinary improvement has 

 taken place in the health of seamen during the last 80 years ; so that three 

 ships can now be kept afloat with only the same number of men, which were 

 formerly required for two. This is due to the improvement in the quality of 

 the food, in combination with other prophylactic means. At present it may 

 safely be affirmed, that it would not be easy to conceive of any diet-scale 

 more adapted to answer the required purpose. The health of crews that 

 have been long afloat, and have been exposed to every variety of external 

 conditions, appears to be preserved (at least when they are under the direc- 

 tion of judicious officers), to the full as well as that of persons subject to 

 similar vicissitudes on shore ; and there can be no complaint of insufficiency 

 of food, although the allowance cannot be regarded as superfluous. It con- 

 sists of from 31 to 35$ ounces of dry nutritious matter daily; of this 26 oz. 

 are vegetable; and the rest animal; 9 ; oz. of salt meat, or 4| oz. fresh, 

 being the allowance of the latter. This is found to be amply sufficient 

 for the support of strength ; and considerable variety is produced, by ex- 

 changing various parts of the diet for other articles. This, however, is some- 

 times done erroneously ; thus 8 oz. of fresh vegetables, which contain only 

 l oz. of solid nutriment, are exchanged for 12 oz. of flour, which is almost 

 all nutritious. Sugar and Cocoa are also allowed ; partly in exchange for a 

 portion of the Spirits formerly served out, the diminution of which, especially 

 in the case of boys, has been attended with great benefit. 



651. A considerable reduction in this amount is of course admissible, 

 where little bodily exertion is required, and where there is less exposure to 

 low temperatures. In the case of Prisoners, the diet should of course be as 

 spare as possible, consistently with health ; but it should be carefully modi- 

 fied, in individual cases, according to several collateral circumstances, such 

 as depression of mind, compulsory labour, previous intemperate habits, and 

 especially the length of confinement. It has been supposed by some, that 



