STOMACH AND INTESTINE. 



393 



of food. While its saline constituents, its 

 potash, and its organic acids, admirably adapt 

 it for that use as an anti-scorbutic which 

 experience points out as one of its most 

 valuable qualities. 



Succulent vegetables. The various succu- 

 lent roots, fruits, and herbs made use of as 

 articles of food, possess a composition which, 

 though different in each particular instance, 

 may still be comprehended in one general 

 description. With little protein or starch, 

 they include a variable quantity of sugar, 

 pectin, gum, organic acids, and salts ; united 

 with what is always a large proportion of 

 water. 



Thus in the class of roots* represented by 

 turnips, carrots, and beet-root, the quantity of 

 albumen is not inconsiderable ; ranging 

 from 1 to 3 per cent.f : and the pectin itself, 

 (C 12 H ]6 O 10 ) is in much more consi- 

 derable quantity. The organic acids of these 

 and the various fruits are too numerous to 

 specify ; but the malic, which is also found 

 in the potato, is one of the most frequent. 

 The fruits contain still less protein and 

 starch than the above roots. The young 

 shoots and leaves of the several varieties of 

 cabbage include starch, and some albumen, as 

 well as sugar. The fixed salts of these various 

 esculent vegetables are little known. In fruits 

 their quantity is small. But in the green 

 vegetables it is larger. And, finally, in the 

 pectinous roots, they form about Ji per cent, 

 of ash ; in which Boussingault has found most 

 of the ordinary acids and bases, with propor- 

 tions somewhat approaching those seen in 

 the potato ; save that lime and soda are in- 

 creased, while phosphoric acid is diminished. 



The nutritive value of these vegetable sub- 

 stances is therefore very considerable. Defi- 

 cient as most of them are in the proteinous 

 principle, they are of course unsuited for the 

 maintenance of nutrition without the admix- 

 ture of other azotized substances. The precise 

 way in which their pectin is applied to the 

 uses of the organism cannot at present be 

 explained. But its composition is so far akin 

 to that of the gum and sugar which accompany 

 it, that we may conjecture it subserves pur- 

 poses similar to those accomplished by these 

 hydrates of carbon. The salts of such vegetables 

 replace those lost by the body ; and, although 

 deficient in phosphates, seem to form what is, 

 in most other respects, a tolerable compen- 

 sation for the waste of excretion. Finally, 

 their organic acids disappear in the blood, 

 in which they probably undergo an oxidation 

 that ultimately converts them into carbonic 

 acid and water. 



With respect to the two latter consti- 

 tuents, namely, salts and acids it is im- 

 portant for us to recollect, that there are 

 many phenomena of health and disease 

 which teach us, far better than our pre- 

 sent knowledge of physiological chemistry, 



* Botanically, of course these parts are not 

 ** roots," though usualJy so termed, 

 t Frerichs, Op. tit. 



what is the true value to the organism 

 of such compounds. The incontrollable 

 longing of Man after variety of diet, appears 

 to find vent chiefly in the cultivation and 

 consumption of esculent vegetables of this 

 class. While scurvy, and other dangerous 

 diseases of the same kind, which are still too 

 prevalent among us, may serve to advise us 

 that, within certain limits, this instinctive 

 taste represents a bodily want, the satisfying 

 of which is not so much a concession to the 

 cravings of luxury, as a payment of the just 

 claims of health. 



The seasonings generally added to food 

 are rarely alimentary in the strict sense of 

 this word. 



Chloride of sodium, or common salt, is, 

 however, a marked exception to this rule ; 

 being habitually taken by most nations, and 

 eagerly sought after by many animals, both 

 wild and domesticated. Its use in reference 

 to digestion may be presumed to depend 

 chiefly on its relation to the acid* of the gastric 

 juice. But the alleged results of its complete 

 withdrawal from the food of criminals, are 

 such as to suggest an antiseptic action of this 

 salt on the contents of the stomach, even 

 independent of that exerted by the gastric 

 juice itself. And the office it subserves with 

 reference to nutrition generally, appears to 

 be a still more obscure one. Its habitual 

 ingestion seems to facilitate the process of 

 fattening, as well as to increase the amount 

 of excretion. The large constituent which it 

 forms in the ash of the blood and of most of 

 the tissues, probably has some reference to 

 all these details. 



The other seasonings chiefly made use of 

 in civilized life may be divided into two 

 classes ; acids, and acrid substances. The 

 former consist of various organic acids ; espe- 

 cially acetic acid or vinegar, and lemon 

 juice. These seem to act mainly by stimu- 

 lating the stomach ; perhaps increasing the 

 acidity, and with this the solvent energy, of 

 the gastric juice. The various acrid sub- 

 stances mustard, pepper, capsicum, garlic, 

 &c. are also supposed to stimulate the 

 secretion of this fluid, by exciting a violent 

 determination of blood to the mucous mem- 

 brane of the stomach. Many of them are 

 irritant poisons, when taken in undue quantity. 



Stimulants. Tea, coffee, and alcohol, are 

 substances which, though taken with the 

 food, are scarcely alimentary in any truer 

 sense than some of the acrid seasonings just 

 alluded to. Indeed, were the practice of 

 chewing tobacco as prevalent as the use of 

 these substances -f, the leaf of this highly 

 poisonous narcotic would be equally entitled 

 to rank in the category of food. Still their 



* Compare pp. 332. and 349. 



t An instance of the partial starvation of a large 

 ship's crew on a long voyage was lately brought 

 under the authors notice, in which the chewers of 

 tobacco were alleged to have endured hunger far 

 better than the other sufferers: whilst the smokers 

 of this narcotic did not enjoy the same advantage. 



