318 DIGESTION. 



digestion of flesh for a much longer period than four or five hours; 

 and this view coincides tolerably closely with the experiments 

 made by Beaumont. Thus, for instance, he found that boiled 

 lamb disappeared from the stomach after 2J hours, boiled beef 

 after 2f hours, roast beef after 3 hours, and broiled beef after 4 

 hours ; on the other hand, roast pork did not disappear from the 

 stomach for 6| hours, while broiled pork disappeared after 3-j 

 hours. If we are able, in some cases, to adduce scientific expla- 

 nations for certain practical dietetic rules which accord tolerably 

 well with Beaumont's observations, the far more considerable dif- 

 ferences which present themselves in all results of this kind seem 

 to invalidate such conclusions ; hence we do not venture to enter 

 minutely into the influence which the different modes of preparing 

 the food, and the different species of animals, exert on the 

 digestibility of the flesh. We must, however, not altogether omit 

 to mention (what has so often been prominently brought forward) 

 that flesh which has been kept lying in vinegar is rendered more 

 digestible, since, as every microscopist knows, the connective tissue 

 and muscular fibre are thus rendered of looser texture ; and that 

 smoked meat is generally far more difficult of digestion than un- 

 smoked, since the pickle in which the meat was placed preparatory 

 to the smoking not only extracts from the flesh a fluid containing 

 certain easily digestible substances, but also renders the fibres 

 themselves harder and more insoluble. 



With regard to the fats, it is tolerably well agreed that they 

 rank amongst the most indigestible matters; physicians have, 

 indeed, always exhibited an extraordinary aversion to permit the 

 use of fatty food to any of their patients, although they see that 

 many fats, as, for instance, the fashionable, but generally rancid, 

 cod-liver oil, is very easily digested. It may readily be conceived 

 from its physical characters, as, for instance, its insolubility in 

 water, and the resistance which it offers to the most powerful re- 

 agents, that fat, as compared with the other simple nutrient 

 substances, is only slowly absorbed ; indeed, even to the most 

 recent times, it has been difficult to form an idea of the mode in 

 which fat undergoes resorption. It is sufficiently clear, from what 

 has been previously stated, that the stomach is not the place 

 where the fat is resorbed, or even where it undergoes any essential 

 changes ; but when it is taken in large quantity, either alone or 

 with other food, it usually remains for a long time in the stomach ; 

 thus Beaumont found beef-suet in St. Martin's stomach after 5? 

 hours. It is not only not digested in the stomach, but often exerts 



