Liebig also, in his Letters on Chemistry, pp. 424 and 425, says:—‘It has now been proved by the most convincing experiments, that gelatine, which by itself is tasteless, and when eaten excites nausea, possesses no nutritive value; that even when accompanied by the savoury constituents of flesh, it is not capable of supporting the vital process, and when added to the usual diet as a substitute for plastic matter, does not increase, but on the contrary diminishes the nutritive value of the food, which it renders insufficient in quantity and inferior in quality; and that its use is hurtful rather than beneficial, because it does not, like the non-nitrogenous substances provided by nature for respiration, disappear in the body without leaving a residue, but overloads with nitrogenous products, the presence of which disturbs and impedes the organic processes.’ And he further observes, that ‘the only difference between this and joiner’s glue is its greater price.’ Jellies no doubt were considered most nutritious during the Peninsular war, but we have learned many things since then, of which our poor soldiers ought to have the benefit.
Portable soup is prepared in a very simple manner. The meat is boiled, and the scum taken off as it rises, until the soup possesses the requisite flavour. ‘It is then suffered to cool, in order that the fat may be separated. In the next place it is mixed with the whites of five or six eggs, and slightly boiled—this operation serves to clarify the liquid, by the removal of opaque particles, which unite with the white of egg, at the time it becomes solid by the heat, and are consequently removed along with it. The liquor is then to be strained through flannel, and evaporated on the water bath, to the consistence of a very thick paste, after which it is spread rather thin upon a smooth stone, then cut into cakes, and lastly dried in a stove, until it becomes brittle. These cakes may be kept four or five years, if defended from moisture. When intended to be used, nothing more is required to be done than to dissolve a sufficient quantity in boiling water.’[2]
For some years past there have been imported into the Continent rather large quantities of dried meat from the southern countries of America, where it is known under the name of assayo. It gives a soup nearly similar to that of fresh meat. Another sort of food which is prepared in Texas, the meat-biscuit, is generally used in the American navy; but, although greatly appreciated at the Great Exhibition of London, it has not yet entered into general use in Europe. It is made of boiled beef free from grease, the liquor of which is evaporated to the consistency of syrup, and this is mixed with wheaten flour in sufficient proportion to form a solid paste. This paste is then spread out by a rolling pin, is pierced with a number of little holes, is cut into the ordinary dimensions of sea biscuits, and then baked and properly dried. The biscuit is eaten dry, or may be broken, boiled in twenty or thirty times its weight in water, for from twenty-five to thirty minutes, and then seasoned with salt or other things.
The following is the process of manufacturing this biscuit:—
There are four wooden caldrons or tubs for boiling the meat and evaporating the liquid or broth—the two for boiling the meat, holding 2,300 gallons, will each boil 7,000 lbs. of meat in twelve to sixteen hours. The other two, for evaporating, will contain some 1,400 gallons each. All the tubs are heated or boiled by steam passing through long coiled iron pipes, supplied at pleasure, either from the escape steam from the engine, or direct from the boiler.
When the meat is so far boiled or macerated, that the liquid or broth contains the entire nutriment, the meaty, or solid portions are separated by a simple process of filtering, so that the broth goes into the evaporator pure and free from fibrous matter. It is then evaporated to a degree of consistency resembling the golden or Stewart’s sugar house syrup, its uniform density being determined by a liquid or syrup gauge. Two pounds of this syrup or extract contains the nutriment of some eleven pounds of meat (including its usual proportion of bone) as first put into the caldron. This is then mixed with the best and finest flour, kneaded and made into biscuit by means of machines. The biscuit is baked upon pans in an oven so constructed as to produce an uniform firmness. The proportion is as two pounds of extract are to three pounds of flour, but by baking, the five pounds of dough is reduced to four pounds of biscuit, and this will make what the inventor claims—the nutriment of over five pounds of meat in one pound of bread, which contains, besides, over ten ounces of flour.
The biscuit resembles in appearance a light coloured sugar-cake. It is packed in air-tight casks or tin canisters of different sizes, part of the biscuit being pulverized by grinding in a mill for the purpose, and then packed with the whole biscuit.
In discussing the extension of our resources of animal food, it is strange to notice that while we eat the blood of pigs and fowls, we throw aside as waste the blood of oxen, sheep, goats, calves, &c. Now blood contains all the principles out of which the tissues are formed, and must, one would therefore imagine, be eminently nutritious. Why prejudice has excluded these, while admitting the blood of pigs, is an anomaly which I cannot understand.
In France, where there are not, as in America, large quantities of animals which are killed simply for the sake of their hides, it would be impossible to prepare or supply at a low price either the assayo or the meat biscuit; but the idea of using the blood of animals killed, which blood is at present wasted without profit, or, at best, is used as manure, might have occurred to some one. M. Brocchieri has conceived this idea. In treating the blood of our slaughter-houses by means which he has invented, and uniting to flour of the best quality, the albumen and fibrine which he extracts from it—he makes bread and biscuits which are easily preserved, and which may be employed to make very nutritious soups.
At the Great Exhibition, in 1851, he produced bon-bons made of the blood of the ox, cow, sheep, and hog; biscuits and patties of the blood of the bull, and delicacies made of calves’ blood. I have specimens of these preserved in my private museum, although I have not ventured to taste them.