313 



diSJ UY. 



[rauiT AS FOOD. 



acid has been observed in several roots, which are 



iUle for the ah.' la oil*. 



;*ragino U fuuud in potatoes, which also remind us 

 of the composition of asparagus, by their containing 

 .icid. 



UliiK- all the inorganic clement* of our bodies, with 

 the f fluorine, ara found in the potato, it ix 



characteristic of turnips that they contain no soda, and 

 only very little iron. By way of compensation, tlu-y 

 possess a Urge quantity of potash, which is also contained 

 in the ashes of potatoes, in a greater proportion than all 

 the other inorganic constituents put together. 



$ 61. Companion of RooU and Vegetable*. In com- 

 paring potatoes and other edible roots with esculent 

 .ililcs, wo find the latter inferior in digestibility and 

 .'.iveiiuss to the former ; for, in the roots, not only 

 are the diuVrent constituents of fat namely, starch, 

 gum, and especially sugar more readily soluble than the 

 c.-llulose of tin' vegetables; but these constituents of 

 fat and albumen, however small tlio proportion of the 

 . may be, are also much moro abundantly present 

 in roots than in leaves and stalks. 



But if we contrast the roots with the group of the 

 more nutritious aliments, as meat, cereal groins, and 

 leguminous seeds, we find even the least substantial 

 aliment of this group more nutritious than any edible roots, 

 liice and moire are not only richer in albuminous sub- 

 stances than roots, but exceed them nearly fourfold in 

 the amount of starch which they contain. 



The edible roots, as well as vegetables and fruit, belong, 

 therefore, to the less nutritious aliments, and may bo 

 united into a second group, the first being formed of 

 meat, bread, And leguminous seeds. 



In this second group, potatoes and carrots, it is true, 

 are distinguished from the other members by their 

 superior nutritiveness, as well as by their digestibility. 

 But, notwithstanding this, what must we think of the 

 ralue of a nutriment in which the albumen and the con- 

 t tituents of fat are contained in an exactly inverse pro- 

 u to that which exists in the blood? It may, 

 indeed, overload the blood and the tissues with fat ; but 

 inasmuch as it provides the blood only scantily with 

 albumen, it conveys no fibrine, and, therefore, no strength 

 to the muscles ; nor can it furnish any albumen or phos- 

 phuretted fat to the brain. Now what would be the 

 consequence if we were to accustom ourselves to eat such 

 a quantity of potatoes as would suffice for providing the 

 blood with the requisite proportion of albumen by their 

 means alone 1 It is very obvious if, through this excessive 

 supply, the process of digestion did not come to an entire 

 stand -still, a superabundance of fat would be formed 

 beyond the power of the oxygen to consume ; and this 

 fat would successively absorb from the albuminous sub- 

 stances a part of this vital clement. A barrier would 

 thus be raised against the endless change of matter 

 in the tissues, against nutrition and regressive transfor- 

 mation ; and only a portion of the material, and that 

 the less important one, would take a part in that course 

 of decay and reparation, by which the will and the 

 energy, the movements and the thoughts, are brought 

 to act. 



It is this which so immensely aggravates the weight 

 of poverty. The ill-satisfied want may be tolerated for 

 a time ; the strength of the arm may by strenuous 

 efforts, and with the hope of obtaining better food, for a 

 time uphold the fainting courage ; but can a lazy potato- 

 fed-blood confer on the muscle the power necessary for 

 this labour; or on the brain the necessary vivifying 

 impulses of hope ? 



5 02. Tastt. It is not only the peculiar taste which is 

 produced by the volatile oils existing, as above stated, 

 in the several roots ; that taste is but the first link to a 

 long scries of impressions effected by these oils upon I In- 

 ' body. The different kinds of leeks, onions, an I 

 accelerate the pulse ; the oil is convoyed to the : 

 with the blood, and the irritability is increased ; the 

 . of the oils is communicated to the breath ; ami, 

 apart from the flatulent risings caused by the i 

 and horse-radish, it may bo perceived immediately, from 



the exhaled air, that -Its, or garlic, have boon 



eaten. Through the action of these oils the l.i 

 abstract much water from the blood ; for the diuretic 

 effect of these roots is well known. 



J 63. Fruit. Vying in scent and colour with the 

 flowers of the fields, fragrant fruits decorate ourorehards ; 

 niul though the savoury mango, and other tropical fruits 

 do not tempt the tongue in our climate, still the appli- 

 ances of horticultural skill have given an exquisite 

 delicacy to our apples and pears, and transplanted the 

 cherry and peach from Asia Minor ; while active com- 

 merce provides us with the orange, and the lemon, and 

 pine-apple. 



The nutritive and refreshing qualities of so many 

 noble fruits have not escaped the researches of chemists. 

 The cause, how over, of so many subtle varieties of ; 

 and odour has not yet received a satisfactory chemical 

 elucidation. It is true we know the volatile oil which 

 causes the peel of lemons and oranges to throw out afar 

 their peculiar fragrance ; it is true we know that some 

 fine sorts of ether reside in raspberries and peaches, 

 which are now abundantly produced by chemical means, 

 and used for flavouring purposes. Yet if the causes of 

 variety are to bo as lucid to our mind as the variety 

 itself is delightful to our palate, much remains to bo 

 investigated. 



Cellulose, gum, anil sugar constituents of fat, there- 

 fore, both of difficult and of easy digestion are to be 

 found in all fruits, as in apples, in stone-fruit, in berries, 

 in oranges, and in melons. These components are asso- 

 ciated with but a small proportion of albumen ; it is 

 even smaller here than in vegetables, though here and 

 there, as in apricots, it is greater. The proportion of 

 water contained in fruits, is intermediate between that 

 contained in edible roots and vegetables. 



Fruit-marrow, or pectoso, a substance wo have 'already 

 specified as found in several roots, is abundantly present 

 in all unripe fruits. While the fruits are ripening, this 

 is gradually transformed into the constituent of A 

 table gelatine (pectin*), which, by boiling, becomes gela- 

 tine acid. 



Several peculiar colouring matters, together with wax, 

 produce the brilliancy of colour in the peel of cherries 

 and apples. Like a film, they cover the skin ; a touch 

 of the finger deprives the peach of that tender waxy 

 bloom, which in fragrance surrounds the fruit with a 

 virgin-like adornment. 



Different acids, supported by several salts, cool and 

 refresh our thirsty tongues ; as, for instance, malic acid, 

 present in almost every fruit, especially in apricots and 

 peaches, in apples and pears, in gooseberries and cur- 

 rants; citric acid, present in lemons and raspberries, 

 grapes and pine-apples ; and tartoric acid, in grapes and 

 figs. The skin of grapes derives its astringent taste 

 from the tannic acid, which, in many other fruits, as in 

 acorns, produces a taste entirely bitter. 



Almonds and nuts, as well as the kernels of stone- 

 fruit, contain an albuminous compound (emulsine), which 

 we may call ferment of almonds. In a temperature some- 

 what raised, this ferment of nlmonds causes another 

 nitrogenised substance, contained in bitter almonds and 

 in kernels of peaches, and called the almond-/irh 

 (amygdaline), to undergo a fermentation, by which the 

 lo oil of bitter almonds and hydrocyanic acid are 

 foi mi ii. 



As chestnuts are distinguished by their amount of 

 starch, so almonds and nuts ore characterised by their 

 abundance of on oil consisting of oleine and margarine. 

 It Is only from compliance with custom that we place 

 almonds, nuts, and chestnuts in the group of fruits, as 

 their very slight proportionate amount of water decidedly 

 approximates them to the group of the more nutritive 

 aliments. 



64. Degrees of Acidity. Ripe and sweet, sour and 

 unripe, are, in popular language, words of the same sig- 

 uilieatiou ; wrongly, if we ascribe the degree of acidity 

 proportionate abundance of sourness ; for in tho 

 ripe fruit, tho proportion of acid is very often increased ; 

 but the sugar, which lias augmented in a ttill greater 



