NATURE OF CHYMIFICATION. 505 



standing at rest a few minutes, a fine sediment, of the colour of the meat, sub- 

 sided to the bottom of the vial. A piece of beef, exactly similar to that placed 

 in the vial, was introduced into the stomach, through the aperture, at the same 

 time. At 12 o'clock it was withdrawn, and found to be as little atFected by 

 digestion as that in the vial ; there was little or no difference in their appear- 

 ance. It was returned to the stomach; and, on the string being drawn out at 

 1 o'clock P.M., the meat was found to be all completely digested and gone. 

 The effect of the gastric juiee on the piece of meat suspended in the stomach, 

 was exactly similar to that in the vial, only more rapid after the first half 

 hour, and sooner completed. Digestion commenced on, and was confined to, 

 the surface entirely in both situations. Agitation accelerated the solution in the 

 vial, by removing the coat that was digested on the surface, enveloping the 

 remainder of the meat in the gastric fluid, and giving this fluid access to the 

 undigested portions."* Many variations were made in other experiments ; 

 some of which strikingly displayed the effects of thorough mastication, in 

 aiding both natural and artificial digestion. 



666. The attempt was made by Dr. Beaumont, to determine the relative 

 digestibility of different articles of diet, by observing the length of time re- 

 quisite for their solution. But, as he himself points out, the rapidity of diges- 

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

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

 health, the condition of the mind, and the nature of the weather, that a much 

 more extended inquiry would be necessary to arrive at results to be depended 

 on. Some important inferences of a general character, however, may be 

 drawn from his inquiries. 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 difficult of digestion, interferes with the solution of food that would other- 

 wise 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.'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 Veddahs or wild hunters of Ceylon, 

 on the same principle, mingled 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 practice, 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 conform- 

 able 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. Dr. Beaumont also ascertained that 

 moderate exercise facilitates digestion, though severe and fatiguing exercise 



* Experiments 2 and 3 of First Series. 

 43 



