340 OF DIGESTION AND NUTRITIVE ABSORPTION. 



452. That the foregoing table can only be regarded as approximative, is 

 shown by the fact substantiated by Dr. Beaumont, that the rapidity of diges- 

 tion varies greatly according to the quantity eaten, the nature and amount of 

 the previous exercise, the interval since the preceding meal, the state of health 

 and of the weather, and the condition of the mind. In scarcely any of the 

 experiments have these circumstances been carefully noted ; and, as Dr. B. 

 himself remarks, "the only way of insuring 4 minuteness and accuracy, as to 

 the relative digestibility of "different kinds of diet, would be to try the effect of 

 the gastric juice, in a series of experiments, first on one article of diet, and 

 then on another, repeating and adapting them to meet all the various condi- 

 tions of the stomach, and the vicissitudes and irregularities of the system, until 

 the whole range should be completed, a Herculean task, which it would take 

 years to accomplish." Some important inferences, however, may be drawn 

 from the foregoing results. It seems to be a general rule, that the flesh of wild 

 animals is more easy of digestion than that of the domesticated races which 

 approach them most nearly. This may, perhaps, be partly attributed to the 

 small quantity of fatty matter that is mixed up with the flesh of the former, 

 whilst that of the latter is largely pervaded by it. For it appears from Dr. 

 B.'s experiments, that the presence in the stomach of any substance which is 

 difijcult of digestion, interferes with the solution of food that would otherwise 

 be soon reduced. It seems that, on the whole, beef is more speedily reduced 

 than mutton, and mutton sooner than either veal or pork. Fowls are far from 

 possessing the digestibility that is ordinarily imputed to them; but turkey is, of 

 all kinds of flesh except venison, the most soluble. Dr. B. has also ascertained 

 that moderate exercise facilitates digestion, though severe and fatiguing exercise 

 retards it. If even moderate exercise be taken immediately after a full meal, 

 however, it is probably rather injurious than beneficial ; but if an hour be per- 

 mitted to elapse, or if the quantity of food taken has been small, it is of decided 

 benefit. 



453. The presence of Bile in the stomach has been regarded by some phy- 

 siologists as an ordinary occurrence during digestion ; but according to Dr. B. 

 this is not the case, except in morbid conditions of the organ, or after a long 

 perseverance in the use of fat or oily food. It is not impossible that the con- 

 version of such food may be aided by the bile, the free alkali of which will 

 have a chemical operation upon it. Dr. A. Combe suggests whether the 

 circumstance of the peculiar digestibility of a piece of fat bacon in certain 

 forms of dyspepsia, may not be accounted for by the presence of bile in the 

 stomach in this condition. Dr. B.'s experiments further show that bulk is as 

 necessary for healthy digestion, as the presence of the nutrient principle itself. 

 This fact has been long known by experience to uncivilized nations. The 

 Kamschatdales, for example, are in the habit of mixing earth or saw-dust with 

 the train-oil, on which alone they are frequently reduced to live. The Ved- 

 dahs, or wild hunters of Ceylon, on the same principle, mingle the pounded 

 fibres of soft and decayed wood with the honey, on which they feed when 

 meat is not to be had ; and on one of them being asked the reason of the prac- 

 tice, he replied, "I cannot tell you, but I know that the belly must be filled." 

 It is further shown by Dr. B., that soups and fluid diet are not more readily 

 chymified than solid aliment, and are not alone fit for the support of the system ; 

 and this, also, is conformable to the well-known results of experience ; for a 

 dyspeptic patient will frequently reject chicken-broth, when he can retain solid 

 food or a richer soup. Perhaps, as Dr. A. Combe remarks, the little support 

 gained from fluid diet, is due to the rapid absorption of the watery part of it ; 

 so that the really nutritious portion is left in too soft and concentrated a state to 

 excite the healthy action of the stomach. 



454. From the foregoing statements we may conclude, that the process by 



