Fossil Food

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Title:     Fossil Food
Author: Grant Allen [More Titles by Allen]

There is something at first sight rather ridiculous in the idea of eating a fossil. To be sure, when the frozen mammoths of Siberia were first discovered, though they had been dead for at least 80,000 years (according to Dr. Croll's minimum reckoning for the end of the great ice age), and might therefore naturally have begun to get a little musty, they had nevertheless been kept so fresh, like a sort of prehistoric Australian mutton, in their vast natural refrigerators, that the wolves and bears greedily devoured the precious relics for which the naturalists of Europe would have been ready gladly to pay the highest market price of best beefsteak. Those carnivorous vandals gnawed off the skin and flesh with the utmost appreciation, and left nothing but the tusks and bones to adorn the galleries of the new Natural History Museum at South Kensington. But then wolves and bears, especially in Siberia, are not exactly fastidious about the nature of their meat diet. Furthermore, some of the bones of extinct animals found beneath the stalagmitic floor of caves, in England and elsewhere, presumably of about the same age as the Siberian mammoths, still contain enough animal matter to produce a good strong stock for antediluvian broth, which has been scientifically described by a high authority as pre-Adamite jelly. The congress of naturalists at Tuebingen a few years since had a smoking tureen of this cave-bone soup placed upon the dinner-table at their hotel one evening, and pronounced it with geological enthusiasm 'scarcely inferior to prime ox-tail.' But men of science, too, are accustomed to trying unsavoury experiments, which would go sadly against the grain with less philosophic and more squeamish palates. They think nothing of tasting a caterpillar that birds will not touch, in order to discover whether it owes its immunity from attack to some nauseous, bitter, or pungent flavouring; and they even advise you calmly to discriminate between two closely similar species of snails by trying which of them when chewed has a delicate _soupcon_ of oniony aroma. So that naturalists in this matter, as the children say, don't count: their universal thirst for knowledge will prompt them to drink anything, down even to _consomme_ of quaternary cave-bear.

There is one form of fossil food, however, which appears constantly upon all our tables at breakfast, lunch, and dinner, every day, and which is so perfectly familiar to every one of us that we almost forget entirely its immensely remote geological origin. The salt in our salt-cellars is a fossil product, laid down ages ago in some primaeval Dead Sea or Caspian, and derived in all probability (through the medium of the grocer) from the triassic rocks of Cheshire or Worcestershire. Since that thick bed of rock-salt was first precipitated upon the dry floor of some old evaporated inland sea, the greater part of the geological history known to the world at large has slowly unrolled itself through incalculable ages. The dragons of the prime have begun and finished their long (and Lord Tennyson says slimy) race. The fish-like saurians and flying pterodactyls of the secondary period have come into existence and gone out of it gracefully again. The whole family of birds has been developed and diversified into its modern variety of eagles and titmice. The beasts of the field have passed through sundry stages of mammoth and mastodon, of sabre-toothed lion and huge rhinoceros. Man himself has progressed gradually from the humble condition of a 'hairy arboreal quadruped'--these bad words are Mr. Darwin's own--to the glorious elevation of an erect, two-handed creature, with a county suffrage question and an intelligent interest in the latest proceedings of the central divorce court. And after all those manifold changes, compared to which the entire period of English history, from the landing of Julius Caesar to the appearance of this present volume (to take two important landmarks), is as one hour to a human lifetime, we quietly dig up the salt to-day from that dry lake bottom and proceed to eat it with the eggs laid by the hens this morning for this morning's breakfast, just as though the one food-stuff were not a whit more ancient or more dignified in nature than the other. Why, mammoth steak is really quite modern and commonplace by the side of the salt in the salt-cellar that we treat so cavalierly every day of our ephemeral existence.

The way salt got originally deposited in these great rock beds is very well illustrated for us by the way it is still being deposited in the evaporating waters of many inland seas. Every schoolboy knows of course (though some persons who are no longer schoolboys may just possibly have forgotten) that the Caspian is in reality only a little bit of the Mediterranean, which has been cut off from the main sea by the gradual elevation of the country between them. For many ages the intermediate soil has been quite literally rising in the world; but to this day a continuous chain of salt lakes and marshes runs between the Caspian and the Black Sea, and does its best to keep alive the memory of the time when they were both united in a single basin. All along this intervening tract, once sea but now dry land, banks of shells belonging to kinds still living in the Caspian and the Black Sea alike testify to the old line of water communication. One fine morning (date unknown) the intermediate belt began to rise up between them; the water was all pushed off into the Caspian, but the shells remained to tell the tale even unto this day.

Now, when a bit of the sea gets cut off in this way from the main ocean, evaporation of its waters generally takes place rather faster than the return supply of rain by rivers and lesser tributaries. In other words, the inland sea or salt lake begins slowly to dry up. This is now just happening in the Caspian, which is in fact a big pool in course of being slowly evaporated. By-and-by a point is reached when the water can no longer hold in solution the amount of salts of various sorts that it originally contained. In the technical language of chemists and physicists it begins to get supersaturated. Then the salts are thrown down as a sediment at the bottom of the sea or lake, exactly as crust formed on the bottom of a kettle. Gypsum is the first material to be so thrown down, because it is less soluble than common salt, and therefore sooner got rid of. It forms a thick bottom layer in the bed of all evaporating inland seas; and as plaster of Paris it not only gives rise finally to artistic monstrosities hawked about the streets for the degradation of national taste, but also plays an important part in the manufacture of bonbons, the destruction of the human digestion, and the ultimate ruin of the dominant white European race. Only about a third of the water in a salt lake need be evaporated before the gypsum begins to be deposited in a solid layer over its whole bed; it is not till 93 per cent. of the water has gone, and only 7 per cent. is left, that common salt begins to be thrown down. When that point of intensity is reached, the salt, too, falls as a sediment to the bottom, and there overlies the gypsum deposit. Hence all the world over, wherever we come upon a bed of rock salt, it almost invariably lies upon a floor of solid gypsum.

The Caspian, being still a very respectable modern sea, constantly supplied with fresh water from the surrounding rivers, has not yet begun by any means to deposit salt on its bottom from its whole mass; but the shallow pools and long bays around its edge have crusts of beautiful rose-coloured salt-crystals forming upon their sides; and as these lesser basins gradually dry up, the sand, blown before the wind, slowly drifts over them, so as to form miniature rock-salt beds on a very small scale. Nevertheless, the young and vigorous Caspian only represents the first stage in the process of evaporation of an inland sea. It is still fresh enough to form the abode of fish and mollusks; and the irrepressible young lady of the present generation is perhaps even aware that it contains numbers of seals, being in fact the seat of one of the most important and valuable seal-fisheries in the whole world. It may be regarded as a typical example of a yet youthful and lively inland sea.

The Dead Sea, on the other hand, is an old and decrepit salt lake in a very advanced state of evaporation. It lies several feet below the level of the Mediterranean, just as the Caspian lies several feet below the level of the Black Sea; and as in both cases the surface must once have been continuous, it is clear that the water of either sheet must have dried up to a very considerable extent. But, while the Caspian has shrunk only to 85 feet below the Black Sea, the Dead Sea has shrunk to the enormous depth of 1,292 feet below the Mediterranean. Every now and then, some enterprising De Lesseps or other proposes to dig a canal from the Mediterranean to the Dead Sea, and so re-establish the old high level. The effect of this very revolutionary proceeding would be to flood the entire Jordan Valley, connect the Sea of Galilee with the Dead Sea, and play the dickens generally with Scripture geography, to the infinite delight of Sunday school classes. Now, when the Dead Sea first began its independent career as a separate sheet of water on its own account, it no doubt occupied the whole bed of this imaginary engineers' lake--spreading, if not from Dan to Beersheba, at any rate from Dan to Edom, or, in other words, along the whole Jordan Valley from the Sea of Galilee and even the Waters of Merom to the southern desert. (I will not insult the reader's intelligence and orthodoxy by suggesting that perhaps he may not be precisely certain as to the exact position of the Waters of Merom; but I will merely recommend him just to refresh his memory by turning to his atlas, as this is an opportunity which may not again occur.) The modern Dead Sea is the last shrunken relic of such a considerable ancient lake. Its waters are now so very concentrated and so very nasty that no fish or other self-respecting animal can consent to live in them; and so buoyant that a man can't drown himself, even if he tries, because the sea is saturated with salts of various sorts till it has become a kind of soup or porridge, in which a swimmer floats, will he nill he. Persons in the neighbourhood who wish to commit suicide are therefore obliged to go elsewhere: much as in Tasmania, the healthiest climate in the world, people who want to die are obliged to run across for a week to Sydney or Melbourne.

The waters of the Dead Sea are thus in the condition of having already deposited almost all their gypsum, as well as the greater part of the salt they originally contained. They are, in fact, much like sea water which has been boiled down till it has reached the state of a thick salty liquid; and though most of the salt is now already deposited in a deep layer on the bottom, enough still remains in solution to make the Dead Sea infinitely salter than the general ocean. At the same time, there are a good many other things in solution in sea water besides gypsum and common salt; such as chloride of magnesia sulphate of potassium, and other interesting substances with pretty chemical names, well calculated to endear them at first sight to the sentimental affections of the general public. These other by-contents of the water are often still longer in getting deposited than common salt; and, owing to their intermixture in a very concentrated form with the mother liquid of the Dead Sea, the water of that evaporating lake is not only salt but also slimy and fetid to the last degree, its taste being accurately described as half brine, half rancid oil. Indeed, the salt has been so far precipitated already that there is now five times as much chloride of magnesium left in the water as there is common salt. By the way, it is a lucky thing for us that these various soluble minerals are of such constitution as to be thrown down separately at different stages of concentration in the evaporating liquid; for, if it were otherwise, they would all get deposited together, and we should find on all old salt lake beds only a mixed layer of gypsum, salt, and other chlorides and sulphates, absolutely useless for any practical human purpose. In that case, we should be entirely dependent upon marine salt pans and artificial processes for our entire salt supply. As it is, we find the materials deposited one above another in regular layers; first, the gypsum at the bottom; then the rock-salt; and last of all, on top, the more soluble mineral constituents.

The Great Salt Lake of Utah, sacred to the memory of Brigham Young, gives us an example of a modern saline sheet of very different origin, since it is in fact not a branch of the sea at all, but a mere shrunken remnant of a very large fresh-water lake system, like that of the still-existing St. Lawrence chain. Once upon a time, American geologists say, a huge sheet of water, for which they have even invented a definite name, Lake Bonneville, occupied a far larger valley among the outliers of the Rocky Mountains, measuring 300 miles in one direction by 180 miles in the other. Beside this primitive Superior lay a second great sheet--an early Huron--(Lake Lahontan, the geologists call it) almost as big, and equally of fresh water. By-and-by--the precise dates are necessarily indefinite--some change in the rainfall, unregistered by any contemporary 'New York Herald,' made the waters of these big lakes shrink and evaporate. Lake Lahontan shrank away like Alice in Wonderland, till there was absolutely nothing left of it; Lake Bonneville shrank till it attained the diminished size of the existing Great Salt Lake. Terrace after terrace, running in long parallel lines on the sides of the Wahsatch Mountains around, mark the various levels at which it rested for awhile on its gradual downward course. It is still falling indeed; and the plain around is being gradually uncovered, forming the white salt-encrusted shore with which all visitors to the Mormon city are so familiar.

But why should the water have become briny? Why should the evaporation of an old Superior produce at last a Great Salt Lake? Well, there is a small quantity of salt in solution even in the freshest of lakes and ponds, brought down to them by the streams or rivers; and, as the water of the hypothetical Lake Bonneville slowly evaporated, the salt and other mineral constituents remained behind. Thus the solution grew constantly more and more concentrated, till at the present day it is extremely saline. Professor Geikie (to whose works the present paper is much indebted) found that he floated on the water in spite of himself; and the under sides of the steps at the bathing-places are all encrusted with short stalactites of salt, produced from the drip of the bathers as they leave the water. The mineral constituents, however, differ considerably in their proportions from those found in true salt lakes of marine origin; and the point at which the salt is thrown down is still far from having been reached. Great Salt Lake must simmer in the sun for many centuries yet before the point arrives at which (as cooks say) it begins to settle.

That is the way in which deposits of salt are being now produced on the world's surface, in preparation for that man of the future who, as we learn from a duly constituted authority, is to be hairless, toothless, web-footed, and far too respectable ever to be funny. Man of the present derives his existing salt-supply chiefly from beds of rock-salt similarly laid down against his expected appearance some hundred thousand aeons or so ago. (An aeon is a very convenient geological unit indeed to reckon by; as nobody has any idea how long it is, they can't carp at you for a matter of an aeon or two one way or the other.) Rock-salt is found in most parts of the world, in beds of very various ages. The great Salt Range of the Punjaub is probably the earliest in date of all salt deposits; it was laid down at the bottom of some very ancient Asiatic Mediterranean, whose last shrunken remnant covered the upper basin of the Indus and its tributaries during the Silurian age. Europe had then hardly begun to be; and England was probably still covered from end to end by the primaeval ocean. From this very primitive salt deposit the greater part of India and Central Asia is still supplied; and the Indian Government makes a pretty penny out of the dues in the shape of the justly detested salt-tax--a tax especially odious because it wrings the fraction of a farthing even from those unhappy agricultural labourers who have never tasted ghee with their rice.

The thickness of the beds in each salt deposit of course depends entirely upon the area of the original sea or salt-lake, and the length of time during which the evaporation went on. Sometimes we may get a mere film of salt; sometimes a solid bed six hundred feet thick. Perfectly pure rock-salt is colourless and transparent; but one doesn't often find it pure. Alas for a degenerate world! even in its original site, Nature herself has taken the trouble to adulterate it beforehand. (If she hadn't done so, one may be perfectly sure that commercial enterprise would have proved equal to the occasion in the long run.) But the adulteration hasn't spoilt the beauty of the salt; on the contrary, it serves, like rouge, to give a fine fresh colour where none existed. When iron is the chief colouring matter, rock-salt assumes a beautiful clear red tint; in other cases it is emerald green or pale blue. As a rule, salt is prepared from it for table by a regular process; but it has become a fad of late with a few people to put crystals of native rock-salt on their tables; and they decidedly look very pretty, and have a certain distinctive flavour of their own that is not unpleasant.

Our English salt supply is chiefly derived from the Cheshire and Worcestershire salt-regions, which are of triassic age. Many of the places at which the salt is mined have names ending in _wich_, such as Northwich, Middlewich, Nantwich, Droitwich, Netherwich, and Shirleywich. This termination _wich_ is itself curiously significant, as Canon Isaac Taylor has shown, of the necessary connection between salt and the sea. The earliest known way of producing salt was of course in shallow pans on the sea-shore, at the bottom of a shoal bay, called in Norse and Early English a wick or wich; and the material so produced is still known in trade as bay-salt. By-and-by, when people came to discover the inland brine-pits and salt mines, they transferred to them the familiar name, a wich; and the places where the salt was manufactured came to be known as wych-houses. Droitwich, for example, was originally such a wich, where the droits or dues on salt were paid at the time when William the Conqueror's commissioners drew up their great survey for Domesday Book. But the good, easy-going mediaeval people who gave these quaint names to the inland wiches had probably no idea that they were really and truly dried-up bays, and that the salt they mined from their pits was genuine ancient bay-salt, the deposit of an old inland sea, evaporated by slow degrees a countless number of ages since, exactly as the Dead Sea and the Great Salt Lake are getting evaporated in our own time.

Such, nevertheless, is actually the case. A good-sized Caspian used to spread across the centre of England and north of Ireland in triassic times, bounded here and there, as well as Dr. Hull can make out, by the Welsh Mountains, the Cheviots, and the Donegal Hills, and with the Peak of Derbyshire and the Isle of Man standing out as separate islands from its blue expanse. (We will beg the question that the English seas were then blue. They are certainly marked so in a very fine cerulean tint on Dr. Hull's map of Triassic Britain.) Slowly, like most other inland seas, this early British Caspian began to lose weight and to shrivel away to ever smaller dimensions. In Devonshire, where it appears to have first dried up, we get no salt, but only red marl, with here and there a cubical cast, filling a hole once occupied by rock-salt, though the percolation of the rain has long since melted out that very soluble substance, and replaced it by a mere mould in the characteristic square shape of salt crystals. But Worcestershire and Cheshire were the seat of the inland sea when it had contracted to the dimensions of a mere salt lake, and begun to throw down its dissolved saline materials. One of the Cheshire beds is sometimes a hundred feet thick of almost pure and crystalline rock-salt. The absence of fossils shows that animals must have had as bad a time of it there as in the Dead Sea of our modern Palestine. The Droitwich brine-pits have been known for many centuries, since they were worked (and taxed) even before the Norman Conquest, as were many other similar wells elsewhere. But the actual mining of rock-salt as such in England dates back only as far as the reign of King Charles II. of blessed memory, or more definitely to the very year in which the 'Pilgrim's Progress' was conceived and written by John Bunyan. During that particular summer, an enterprising person at Nantwich had sunk a shaft for coal, which he failed to find; but on his way down he came unexpectedly across the bed of rock-salt, then for the first time discovered as a native mineral. Since that fortunate accident the beds have been so energetically worked and the springs so energetically pumped that some of the towns built on top of them have got undermined, and now threaten from year to year, in the most literal sense, to cave in. In fact, one or two subsidences of considerable extent have already taken place, due in part no doubt to the dissolving action of rain water, but in part also to the mode of working. The mines are approached by a shaft; and, when you get down to the level of the old sea bottom, you find yourself in a sort of artificial gallery, whose roof, with all the world on top of it, is supported every here and there by massive pillars about fifteen feet thick. Considering that the salt lies often a hundred and fifty yards deep, and that these pillars have to bear the weight of all that depth of solid rock, it is not surprising that subsidences should sometimes occur in abandoned shafts, where the water is allowed to collect, and slowly dissolve away the supporting columns.

Salt is a necessary article of food for animals, but in a far less degree than is commonly supposed. Each of us eats on an average about ten times as much salt as we actually require. In this respect popular notions are as inexact as in the very similar case of the supply of phosphorus. Because phosphorus is needful for brain action, people jump forthwith to the absurd conclusion that fish and other foods rich in phosphates ought to be specially good for students preparing for examination, great thinkers, and literary men. Mark Twain indeed once advised a poetical aspirant, who sent him a few verses for his critical opinion, that fish was very feeding for the brains; he would recommend a couple of young whales to begin upon. As a matter of fact, there is more phosphorus in our daily bread than would have sufficed Shakespeare to write 'Hamlet,' or Newton to discover the law of gravitation. It isn't phosphorus that most of us need, but brains to burn it in. A man might as well light a fire in a carriage, because coal makes an engine go, as hope to mend the pace of his dull pate by eating fish for the sake of the phosphates.

The question still remains, How did the salt originally get there? After all, when we say that it was produced, as rock-salt, by evaporation of the water in inland seas, we leave unanswered the main problem, How did the brine in solution get into the sea at all in the first place? Well, one might almost as well ask, How did anything come to be upon the earth at any time, in any way? How did the sea itself get there? How did this planet swim into existence at all? In the Indian mythology the world is supported upon the back of an elephant, who is supported upon the back of a tortoise; but what the tortoise in the last resort is supported upon the Indian philosophers prudently say not. If we once begin thus pushing back our inquiries into the genesis of the cosmos, we shall find our search retreating step after step _ad infinitum_. The negro preacher, describing the creation of Adam, and drawing slightly upon his imagination, observed that when our prime forefather first came to consciousness he found himself 'sot up agin a fence.' One of his hearers ventured sceptically to ejaculate, 'Den whar dat fence come from, ministah?' The outraged divine scratched his grey wool reflectively for a moment, and replied, after a pause, with stern solemnity, 'Tree more ob dem questions will undermine de whole system ob teology.'

However, we are not permitted humbly to imitate the prudent reticence of the Indian philosophers. In these days of evolution hypotheses, and nebular theories, and kinetic energy, and all the rest of it, the question why the sea is salt rises up irrepressible and imperatively demands to get itself answered. There was a sapient inquirer, recently deceased, who had a short way out of this difficulty. He held that the sea was only salt because of all the salt rivers that run into it. Considering that the salt rivers are themselves salted by passing through salt regions, or being fed by saline springs, all of which derive their saltness from deposits laid down long ago by evaporation from earlier seas or lake basins, this explanation savours somewhat of circularity. It amounts in effect to saying that the sea is salt because of the large amount of saline matter which it holds in solution. Cheese is also a caseous preparation of milk; the duties of an archdeacon are to perform archidiaconal functions; and opium puts one to sleep because it possesses a soporific virtue.

Apart from such purely verbal explanations of the saltness of the sea, however, one can only give some such account of the way it came to be 'the briny' as the following:--

This world was once a haze of fluid light, as the poets and the men of science agree in informing us. As soon as it began to cool down a little, the heavier materials naturally sank towards the centre, while the lighter, now represented by the ocean and the atmosphere, floated in a gaseous condition on the outside. But the great envelope of vapour thus produced did not consist merely of the constituents of air and water; many other gases and vapours mingled with them, as they still do to a far less extent in our existing atmosphere. By-and-by, as the cooling and condensing process continued, the water settled down from the condition of steam into one of a liquid at a dull red heat. As it condensed, it carried down with it a great many other substances, held in solution, whose component elements had previously existed in the primitive gaseous atmosphere. Thus the early ocean which covered the whole earth was in all probability not only very salt, but also quite thick with other mineral matters close up to the point of saturation. It was full of lime, and raw flint, and sulphates, and many other miscellaneous bodies. Moreover, it was not only just as salt as at the present day, but even a great deal salter. For from that time to this evaporation has constantly been going on in certain shallow isolated areas, laying down great beds of gypsum and then of salt, which still remain in the solid condition, while the water has, of course, been correspondingly purified. The same thing has likewise happened in a slightly different way with the lime and flint, which have been separated from the water chiefly by living animals, and afterwards deposited on the bottom of the ocean in immense layers as limestone, chalk, sandstone, and clay.

Thus it turns out that in the end all our sources of salt-supply are alike ultimately derived from the briny ocean. Whether we dig it out as solid rock-salt from the open quarries of the Punjaub, or pump it up from brine-wells sunk into the triassic rocks of Cheshire, or evaporate it direct in the salt-pans of England and the shallow _salines_ of the Mediterranean shore, it is still at bottom essentially sea-salt. However distant the connection may seem, our salt is always in the last resort obtained from the material held in solution in some ancient or modern sea. Even the saline springs of Canada and the Northern States of America, where the wapiti love to congregate, and the noble hunter lurks in the thicket to murder them unperceived, derive their saltness, as an able Canadian geologist has shown, from the thinly scattered salts still retained among the sediments of that very archaic sea whose precipitates form the earliest known life-bearing rocks. To the Homeric Greek, as to Mr. Dick Swiveller, the ocean was always the briny: to modern science, on the other hand (which neither of those worthies would probably have appreciated at its own valuation), the briny is always the oceanic. The fossil food which we find to-day on all our dinner-tables dates back its origin primarily to the first seas that ever covered the surface of our planet, and secondarily to the great rock deposits of the dried-up triassic inland sea. And yet even our men of science habitually describe that ancient mineral as common salt.

[The end]
Grant Allen's essay: Fossil Food

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