On food : four Cantor lectures, delivered before the Society for the Encouragement of Arts, Manufactures, and Commerce / by H. Letheby.
- Henry Letheby
- Date:
- 1868
Licence: Public Domain Mark
Credit: On food : four Cantor lectures, delivered before the Society for the Encouragement of Arts, Manufactures, and Commerce / by H. Letheby. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![i3 nitrogenoias. They are chiefly valuable for their anti- jcorbutie properties, and for their quality of flavouring insipid food, and diluting strong ones. Banana and bread-fruit are also valuable esculent Poods, and are largely used in the tropics. The former lontains about 27 per cent, of solid matter, of nearly the iame nutritive value as rice. About 6^ lbs. of the fresh Tuit, or 2 lbs. of the dry meal, with a quarter of a pound )f salt meat or fish, is a common allowance for a labourer. - The bread-fruit is largely eaten by the natives of the ?;> 'ndian Archipelago, and of the Islands of the South ^•3 Sea. There are several varieties of it which come into M leason at different times. It is very juicy, containing ■'■i ibout 80 per cent, of water, and is generally gathered )efore it is ripe, when the starch is in a mealy condition, ind has not undergone change into sugar. The fresh : i-uit is cooked, by peeling it, wi-apping it in leaves, and s s taking it between hot stones. It then tastes like sweet U (read; but much of the ripe fruit is preserved by peeling El t, cutting it into slices, and packing it very closely in ijj lits in the ground, made water-light, and lined with lanana leaves. After a while it undergoes a sort of ..» ermentation, or, as we should call it from the smell, li lutrefaction, and the fruit settles into a mass, of the con- fii^stence of soft cheese. When it is required for use, it well kneaded, wrapped in leaves, and baked, like the resh fruit, between hot stones. Eipe fruits, as apples, pears, peaches, pine-apples, oranges, ;c., are not of much nutritive value, for they rarely con- ain above 13 per cent, of solid matter, andthis is of no lore value than so much rice, but they have agreeable avours, and serve the purpose of anti-scorbutic drinks Mai e A-lgce.—Everywhere along our coasts, there is bnndance of comparatively nutritious food, which may, jj y a little management, be made palatable. I allude to .J \a sea-weeds; and this Society has distinguished itself jl3 y its efforts to utilize this stock of now almost profitless )od. Judging from the analysis of Dr. Davy and Dr. -pjohn, of Dublin, it would seem that when in a loderately dry condition sea-weeds contain from 18 to 6 per cent, of water; and that the nitrogenous con- tituents amount to from 9J to 16 per cent., while the tarchy matter and sugar average about 66 per cent, ^ese results place sea-weeds among the most nutritrious f vegetable substances ; in fact they are richer in nitro- •enous matter than oatmeal or Indian corn. The varieties of sea-weed at present used are the jJlowing:— Porphyra laciniata and vulgaris, called laver in England 'oke in Ireland, and slouk in Scotland. ' Chondrus crispus, called carrageen or Irish moss, and also earl-moss. Zaminaria digitata, known as sen girdle in England mgle in Scotland, and rcd-ivare in the Ork-neys; and mtnaria saccharina alaria esculenta or bladder-lock, called ISO hen-ware and honeg-ware by the Scotch. Ulva latissima or green laver.—Jihodomenia palmata, or ■<C«e of Scotland.—These, with many others, are eaten y the coast inhabitants of this country and the ontment. _ In some parts of Scotland and Ireland thov hrm a considerable portion of the diet of the poor io prepare them for food, they should first bo steeped I water to remove saline matter ; and in some cases a ttle carbonate of soda added to the water will remove le bitterness. They are then stowed in water or milk itil they are tender and mucilaginous; and they nro )st flavoured with pepper and vinegar. Under the ^don ^■^^^^ ^'^^'^ o°ce a liucury in Ab to the last of the vegetable foods-namely, the 2\ ^^^^ ■'^^it kittle to say; for fev £n '^v ° ^'Shly nutritiou;, vet -Mt of ?!, ^'^^ ^'^ important article of diet. '^ll ^''^ employed at the present time as fla- oTfn^r. /ri^ '' ^tt^^^ the common mush- 'T turkeys and the hvers of geese (FAtedefoUgrm). Sugar and Treacle.—Both of these are very generally consumed on account of their flavoui-ing and fattening qualities Dr. Edward Smith found that 98 per cent, of indoor operatives partook of sugar, to the extent of Ih ozs. per adult, week!}'. 96 per cent, of Scotch labourers use it, and 80 per cent, of Irish. In Wales, also, it is commonly used to an average extent of 6 ozs. per adult weekly; but there is a marked difference in the rate of consumption in the northern and southern portions of the country. In North Wales, for example, the average amount per head is ll;J:0zs.; whereas, in South Wales it is only 3 ozs. The principle use of it is to sweeten tea. Treacle has more flavour than sugar, and it is also cheaper. It is, therefore, more largely employed ; and that description of it properly called, mollasses, which is the draining from the raw or unrefined sugar—treacle being the drainings from refined sugar,—is preferred on accountofitsstronger flavour, and is most usually sold for treacle. They go well with all descriptions of fari- naceous food, as porridge, pudding, dumpling and bie id- Sugar contains from 4 to 10 per cent, of moisture, and treacle about 23. The rest is carbonaceous matter, without nitrogen. They are, therefore, .heat-producing and fattening]agents, and their power, in these resp>^ct3, is about the same as with starch. Wliether thuy can produce disease when used in excess is a matter of doubt; but Dr. Richardson declares that they cause blindness by creating opacity of the lens (caiaractj. Animal Foods.—First on the list of these is milk, a liquid which contains all the elements of food required by the very young, and is therefore regarded as the type or standard of food. In some countries, as Switzerland, it is the chief diet of the peasantr}'; and everywhere, if easily obtained, it is largely consumed. 76 per cent, of the labouring classes of England make use of it; 83 per cent, take it as butter-milk; and 53 per cent, as skimmed-milk. In Wales, the average consumption of it by farm labourers is 4i pints per adult weekly—South Wales averaging only 3 pints, while in North Wales it is 7^. In Scotland the consumption among the labouring classes is still larger, for it amounts to 6j pints per head weekly, and in Ireland it reaches 6f pints. Those who take least of it are the poor in-door operatives of London ; the weavers of Spitalfields, for example, use only about 7'6 oz. per head weekly, and those of Bethnal-green only a fraction above IJ ozs. per head. When examined under the microscope, milk is found to consist of myriads of little globules of butter floating in a clear liquid. On sttvnding for a few hours the oily particles rise to the surface and form a cream, the proportion of which is the test of quality. Cows'-milk is heavier than water in the pro- portion of from 1,030 or 1,032 to 1,000. Asses' milk is the lightest, for its gravity is only about 1,019 ; then comes human milk, 1,020 ; and, lastly, goat and ewes' milk, which is the heaviest of all, from 1,035 to 1.042. The quality of milk varies with the breed of the cow, the nature pf its food, and the time of milking, for after- noon milk is always richer than morning, and the last drawn than the first. Taking, however, the average of a large number of samples, it may be said that cows' milk contains 14 per cent, of solid matter, 4-1 of which are casein, 5 2 sugar, 3-9 butter, and 0-8 saline matter. The relations of nitrogenous to the carbonaceous is 1 to 2'2 ; but as fat is '2\ times more powerful than starch, the relation may be said to bo as 1 to 3-6. \Vhen milk is heated to the boiling temperature, the casein is coagulated to some extent; and if the milk has stood before it is heated, so that the cream may rise, the coagulum includes the cream, and makes tlio so-called Devonshire or clotted cream. Acids also coagulate the casein, and produce a curd, as m the malcing of cheese and curds and whey. Oi eam h rich in butter, as will be seen by reference to Tablo No. 3. It contnins 34 per cent, of solid matter, 267 of which are butter, and its gravity is about 1,013. Skim-milk is the mill? from which the cream has been](https://iiif.wellcomecollection.org/image/b22280364_0011.jp2/full/800%2C/0/default.jpg)
