The Atlantic Monthly, Volume 04, No. 21, July, 1859

A small proportion of sulphur is found in flesh and blood. We prove its presence in the egg by common experience. An egg—from which it escapes more easily than from flesh—discovers its presence by blackening silver, as every housekeeper knows, whose social position is too high for bone egg-spoons or too low for gold ones. This passion which sulphur entertains for silver is very strong, as every one knows who has ever been under that wholesome discipline which had its weekly recurrence at the delightful institution of Dotheboy's Hall; and what Anglo-Saxon ever grew up, innocent of that delectable vernal medicine to which we refer? Has he not found all the silver change in his pocket grow black, suggesting very unpleasant suspicions of bogus coin? The sulphur, being more than is wanted in the economy of the system, has made its escape through every pore in his skin, and, of course, fraternizes with the silver on its way. But it was of the sulphur which is natural to the body and always found there that we were speaking. When the animal dies, and the vital forces give way to chemical affinities, when the phosphorus and the rest take their departure, the sulphur, too, finds itself occupation in new fields of duty.

Chlorine and sodium, two more of the elements of animal structures, produce, in combination, common salt,—without which our food would be so insipid, that we have the best evidence of its being a necessary article of diet. The body has many uses for salt. It is found in the tears, as we are informed by poets, who talk of "briny drops" and "saut, saut tears"; though why there, unless to keep the lachrymal fluid from spoiling, in those persons who bottle up their tears for a long time, we cannot divine.

Perhaps we had better take the rest into consideration together,—the magnesia and iron, and whatever other elements are found in the body. Though some of them are there in minute quantities, the structure cannot exist without them,—and for their constant and sufficient supply our food must provide.

To see what becomes of all these materials after we have done with them, we must extend our inquiries among the articles of ordinary diet and ascertain from what sources we derive the several elements.

It has been sometimes believed that none but animal food contains all the elements required for the support of life. Thanks to Liebig, we have discovered that vegetable substances also, fruits, grains, and roots, contain them all, and, in most cases, in very nearly the same proportions as they are found in animals. We are not lecturing on dietetics; therefore we will not pause to explain why, although either bread or meat alone contains the various materials for flesh and bone, it is better to combine them than to endeavor to subsist on one only.

Whither, then, go these elements when man has done with them? The answer is,—All Nature wants them. Every plant is ready to drink them up, as soon as they have taken forms which bring them within its reach. As gases, they are inhaled by the leaves, or, dissolved in water, they are drunk up by the roots. All plants have not the same appetites, and therefore they can make an amicable division of the supply. Grasses and grains want a large proportion of phosphate of lime, which they convert into husks. Peas and beans have little use for nitrogen, and resign it to others. Cabbages, cauliflowers, turnips, and celery appropriate a large share of the sulphur.

The food of plants and that of animals have this great difference: plants take their nourishment in inorganic form only; animals require to have their food in organic form. That is, all the various minerals, singly or combined, which compose the tissues of plants and animals,—carbon, hydrogen, phosphorus, and the rest, which we have already named,—are taken up by plants in mineral form alone. The food of animals, on the other hand, consists always of organized forms. There is no artificial process by which oxygen, carbon, and hydrogen can be brought into a form suitable for the nourishment of animals. As oxygen, carbon, and hydrogen, they are not food, will not sustain our life, and human art cannot imitate their nutritious combinations. Artificial fibrine and gluten (organic principles) transcend our power of contrivance as far as the philosopher's stone eluded the grasp of the alchemists. We know exactly how many equivalents of oxygen, hydrogen, carbon, and nitrogen enter into the composition of each of the animal elements; but we can no more imitate an organic element than we can form a leaf. What we cannot do the vegetable world does for us. Thus we see why it was necessary that the earth should be clothed with vegetation before animals could be introduced. A field-mouse dies and decays, and its elements are appropriated by the roots around its grave; and we can easily imagine the next generations of mice, the children and grandchildren of the deceased rodent, feasting off the tender bark which was made out of the remains of their parent. The soil of our gardens and the atmosphere above it are full of potential tomatoes, beans, corn, potatoes, and cabbages,—even of peaches of the finest flavor, and grapes whose aroma is transporting.

Plants, as well as animals, have their peculiar tastes. Cut off the supply of phosphate of lime from a field of corn, and it will not grow. You can easily do this by planting the same land with corn for three or four successive years, and your crop will dwindle away to nothing, unless you supply the ground every year with as much of the mineral as the corn takes away from it. All plants have the power of selecting from the soil the materials necessary to their growth; and if they do not find them in the soil, they will not grow. It is now a familiar fact, that, when an old forest of deciduous trees has been felled, evergreens will spring up in their places. The old oaks, hickories, and beeches, as any observer would discover, pass their last years in repose, simply putting out their leaves and bearing a little fruit every year, but making hardly any new wood. An oak may attain to nearly its full size, in spread of branches, in its first two hundred years, and live for five or six hundred years longer in a state of comparative rest. It seems to grow no more, simply because it has exhausted too much of the material for its nourishment from the ground around its roots. At least, we know, that, when we have cut it down, not oaks, but pines, will germinate in the same soil,—pines, which, having other necessities and taking somewhat different food, find a supply in the ground, untouched by their predecessor. Hence the rotation of crops, so much talked of by agriculturists. Before the subject was so well understood, the ground was allowed to lie fallow for a year or two, when the crops began to grow small, that it might recover from the air the elements it had lost. We now adopt the principle of rotation, and plant beans this year where last year we put corn.

It is not merely that plants deprive themselves of their future support by exhausting the neighboring earth of the elements they require. Some of them put into the ground substances which are poisonous to themselves or other plants. Thus, beans and peas pour out from their roots a very notable amount of a certain gum which is not at all suited to their own nourishment,—so that, if we plant beans in the same spot several successive seasons, they thrive very poorly. But this gum appears to be exactly the food for corn; if, therefore, we raise crops of beans and corn alternately, they assist each other. Liebig gives the results of a series of experiments illustrating the reciprocal actions of different species of plants. Various seeds were sprouted in water, in order to observe the nature of the excretions from their roots. It was found "that the water in which plants of the family of the Leguminosae (beans and peas) grew acquired a brown color, from the substance which exuded from their roots. Plants of the same species, placed in water impregnated with these excrements, were impeded in their growth, and faded prematurely; whilst, on the contrary, corn-plants grew vigorously in it, and the color of the water diminished sensibly, so that it appeared as if a certain quantity of the excrements of the Leguminosae had really been absorbed by the corn-plants." The oak, which is the great laboratory of tannin, not only lays up stores of it in its bark and leaves, but its roots discharge into the ground enough of it to tan the rootlets of all plants that venture to put down their suction-hose into the same region, and their spongioles are so effectually closed by this process, that they can no longer perform their office, and the plant that bears them dies. Plants whose roots ramify among the roots of poppies become unwilling opium-eaters, from the exudation of this narcotic principle into the ground, and are stunted, like the children of Gin Lane.

The Aquarium furnishes a very interesting example of the mutual dependence of the three natural kingdoms. Here, in a box holding a few gallons of water and a little atmospheric air, is a miniature world, secluded, and supplying its own wants. Its success depends on the number and character of the animals and plants being so adapted as to secure just the requisite amount of active growth to each to sustain the life of the other: that the plants should be sufficient to support, by the superfluities of their growth, the vegetarians among the animated tribes that surround them; and that all the animal tribes of the aquarium, whether subsisting upon the vegetables or on their smaller and weaker fellow-creatures, should restore to the water in excrements the mineral substances which will enable the plants to make good the daily loss occasioned by the depredations of the sea-rovers that live upon them. Thus an aquarium, its constituents once correctly adjusted, has all the requisites for perpetuity; or rather, the only obstacle to its unlimited continuance is, that it is a mortal, and not a Divine hand, that controls its light and heat.

In the examination of the materials appropriated by plants from the soil, we find that mineral substances are sometimes taken up in solution in larger amount than the growth of the plant and the maturation of its fruit require, and the excess is deposited again, in crystalline form in the substance of the plant. If we cut across a stalk of the garden rhubarb, we can see, with the aid of a microscope, the fine needle-shaped crystals of oxalate of potash lying among the fibres of the plant,—a provision for an extra supply of the oxalic acid which is the source of the intense sourness of this vegetable. When the sap of the sugar-maple is boiled down to the consistence of syrup and allowed to stand, it sometimes deposits a considerable amount of sand; indeed, this is probably always present in some degree, and justifies, perhaps, the occasional complaint of the grittiness of maple-sugar. But it is a native grit, and not chargeable upon the sugar-makers. It is nothing less than flint, which the roots of the maple absorbed, while it was dissolved in water in the soil. The sap, still holding the flint in solution, flows out, clear as water, when the tree is tapped; but when it is concentrated by boiling, the silicious mineral is deposited in little crystals, so that the bottom of the pan appears to be covered with sand. We could not select a more interesting example of the very wide diffusion of some compound substances than this one of silicic acid. It is found in the mineral and vegetable kingdoms. Being a mineral, it cannot be appropriated to animal uses, without being decomposed and transformed into an organic condition; but in the numerous species of plants whose stalks require stiffening against the winds,—in the grasses and canes, including all our grains, the sugar-cane, and the bamboo,—a silicate (an actual flint) is taken up by the roots and stored away in the stalks as a stiffener. The rough, sharp edge of a blade of grass sometimes makes an ugly cut on one's finger by means of the flint it contains. Silex is the chief ingredient in quartz rock, which is so widely diffused over the earth, and enters into the composition of most of the precious stones. The ruby, the emerald, the topaz, the amethyst, chalcedony, carnelian, jasper, agate, and garnet, and all the beautiful varieties of rock crystal, are mostly or entirely silex. Glass is a compound of silex and pearlash. One who is curious in such things may make glass out of a straw, by burning it and heating the ashes with a blowpipe. A little globule of pure glass will form as the ashes are consumed. The following curious instance, quoted by that interesting physiologist, Dr. Carpenter, shows the same effect upon a large scale. A melted mass of glassy substance was found on a meadow between Mannheim and Heidelberg, in Germany, after a thunder-storm. It was, at first, supposed to be a meteor; but, when chemically examined, it proved to consist of silex, combined with potash,—in the form in which it exists in grasses; and, upon further inquiry, it was ascertained that a stack of hay had stood upon the spot, of which nothing remained but the ashes, the whole having been ignited by the lightning.

There is nothing in Nature more striking to the novice than the first suggestions of the various, and apparently contradictory, at least unexpected, positions in which the same mineral is found. Now carbon is one of the minerals whose exchanges are peculiarly interesting. Chemists say that the diamond is the only instance in Nature of pure carbon: it burns in oxygen under the influence of intense heat, and leaves no ashes. Next to this—strange gradation!—is charcoal, which comes within a very little of being a diamond. But just that little interval is apparently so great, that none but a chemist would suspect there was any relationship between them. Then come all those immense beds of coal which compose one of the geological strata of the earth's crust, a stratum that was formed before the appearance of the animated creation, when the earth was clothed with a gigantic forest, whose mighty trunks buried themselves with their fallen leaves, and became, in time, a continuous bed of carbonaceous stone.

If we look at the vegetable and animal kingdoms, we find carbon entering into the composition of every tissue. But there are certain tissues and anatomical elements (as physicians say) which are formed largely of carbon and have no nitrogen whatever. These are oils and fats and everything related to them. What will be chiefly interesting, however, to our readers, is the power of transformation of one of these substances into another. Starch, gum, and sugar can all be changed into fat. The explanation of it is in the fact, that these substances are all chemically alike,—that is, they all have nearly the same proportions of carbon, oxygen, and hydrogen, and no nitrogen; but by slight differences in the combination of these elements, they exist in Nature as so many distinct substances. Their approach to identity is further confirmed by the fact, that starch can be made into gum, and either of them into sugar, in the laboratory. The transformation of starch and gum into sugar is also constantly going on in the ripening of fruits. When country-dames make currant-jellies and currant-wine, they know very well, that, if they allow the berries to get dead-ripe, their jelly will not be so firm as when they seize an early opportunity and gather them when first fully red. They may also have observed that jelly made late, besides being less firm, is much more likely to candy. At first, the currants contain hardly any sugar, but more gum and vegetable jelly (glue); when dead-ripe, they have twelve times as much sugar as at first, and the gum and glue are much diminished. The gummy and gluey materials have been transformed into sugar. Every ripe fruit gives us evidence of the same manufacture of sugar that has gone on under the stimulus of the sun's rays; and in the greatest source of sugar, the cane, the process is the same. A French physician, M. Bernard, has, within the last twelve years, discovered that the liver of animals is constantly making sugar out of all kinds of food, while the lungs are all the time undoing the work of the liver and turning it back into its chemical elements. And although, in the laboratory of the liver, it is discovered that no alimentary substance is quite deficient in sweetness, yet there, as elsewhere, starch and gum yield a far greater amount of it than animal substances.

We have stated that starch and gum can be turned into sugar by art,—but as no chemist has yet succeeded in imitating an animal substance, the change of these three into fat takes place only in the body. There are proofs enough within general observation, that one object of this portion of our diet is the supply of fat. The Esquimaux fattens on his diet of blubber and train-oil; the slaves on the sugar-plantations grow fat in the boiling-season, when they live heartily on sugar; the Chinese grow fat on an exclusively rice diet,—and rice is chiefly starch. But one of the most interesting observations of the transformation of sugar into a fat is that made by Huber upon bees. It was the discovery, that bees make their wax out of honey, and not of pollen, as was formerly believed. When Huber shut up some bees in a close hive, and kept them supplied with pure honey or with sugar alone, they subsisted upon it, and soon began to build the comb. Wax is a fat, and the honey which is eaten by the bee is partly transformed into wax in his body. In about twenty-four hours after his stomach has been filled with honey, thin plates of wax appear on the scales of his abdomen, having oozed through eight little openings in the scales and there hardened. Of this they build their cells.

We have wandered far from the consideration of the propensity of certain species of plants to take up special compound substances from the earth; but the wide-spread silex, with which we set out, displayed so interesting a field of observation, that it could not be resisted, and encouraged a disposition to rove, which has been to us instructive and entertaining. To return to plants,—we find they make use of compounds for certain special ends; but, as we have seen, the whole vegetable kingdom uses the eight or ten primitive elements which it has in common with the animals, and out of these alone forms the infinite variety of products which we derive from it for food and various economical and aesthetical purposes. Among the many processes of Nature whose contemplation fills us with ever new delight, this power of the adaptation of a few means to an infinite number of ends is one of the most enchanting. We endeavor to explain by chemical laws the reduction of the materials which earth and air furnish, to a form in which they can be appropriated by the tree; by endosmose and exosmose we think we have overcome the obstacles to a clear comprehension of the circulation of the sap; and by a cell-theory we believe we have explained the whole growth of wood and leaves and fruit. But what microscope or what alembic shall ever tell us why a collection of tubes and cells in one tree creates the most wholesome and delicious fruit, while in another an organization precisely similar, so far as we can discern, produces only harsh and poisonous berries? why the acacia tribe elaborate their gum, the pine family turpentine, the almond prussic acid, the sorrels oxalic acid? why the tall calisaya-tree of the Andes deposits in its bark the valuable medicine cinchona, and the oak, the hemlock, the tea-plant, and many others, make use of similar repositories to lay up stores of tannic acid? The numberless combinations of the same materials, and the wonderful power which rests in a single seed to bring about with unvarying uniformity its own distinct result, attest to us every day the admirable wisdom and goodness of the Creator.

These regular, every-day transformations of material elements from rock to tree, from tree to man, and back through a continual circuit, would repay us for spending our leisure hours in studying it, with our own eyes as well as with the eyes of others. The glance we have given is sufficiently suggestive to turn the attention of our readers that way. Before parting with them, however, we wish to make a few excursions into the natural world, to follow out some of the more peculiar and unexpected migrations of material atoms. Suppose we take a little marble,—which, in chemical constitution, is carbonate of lime,—that very marble, for instance, which forms the palaces of Venice, against which the waters of the Mediterranean have dashed for so many centuries, and have not dashed in vain. In their perpetual washing, they have worn away the stone and carried off its particles,—an insignificant amount, it is true, but, little as it is, it has not remained unused. For that very carbonate of lime, which once shared the proud state of the "glorious city in the sea," now helps to form the coarse shells of oysters, or is embodied in the vast coral reefs that shoot out from the islands of the West Indies, or is deposited year after year by dying shell-fish, which are slowly carpeting the ocean-bed with their remains. Much of this same Venice marble has doubtless been appropriated by fishes from the sea-water which dissolved it, been transformed into their bones, cast upon the soil of Italy, disintegrated, and imbibed by the thirsty roots of forests in sight of the very walls from which it parted. And who can say that parts of it do not now adorn the necks of some Venetian dames, in coral, or more costly pearls? What says Ariel to the orphaned Ferdinand?

Full fathom five thy father lies;Of his bones are coral made;Those are pearls that were his eyes:Nothing of him that doth fadeBut doth suffer a sea-changeInto something rich and strange.

This is but a hint of the mutability of created things. Marble, sea-shells, the chalk-cliffs of Dover, the limestone fossils which preserve for us animal forms of species long since extinct, the coral formations that are stretching out in dangerous reefs in so many seas of the tropics, are all identical in their chief ingredient, and, as we see, are by natural processes and various accidents constantly interchanging their positions.

It ought to be consoling to those who think a great deal of their bodies, to reflect, that, if we may tend "to base uses," we may also tend to very noble ones. In the course of their transmigrations, the elements of a worthless individual may get into far better company than they have before enjoyed,—may enter into brains that immortalize their owner and redeem the errors of the old possessor. Whoever bases his merit on a long line of ancestors who have nothing but a perpetuated name to boast of, may be likened to the last of many successive tenants of a house who have hired it for their temporary uses. The inheritance of a brave spirit and a noble mind is a sufficient justification for a reasonable pride; but not so with the heritage of materials which are continually interchanging with the clod.

There need be nothing humiliating in such thoughts; the operations of Nature are always admirable. But when the relics of humanity are deliberately appropriated to such mechanical or scientific purposes as we shall relate, before they have entirely lost their original (we should say latest) form, then most men would look upon the act as in some sort a desecration. With what holy horror would the ancient Egyptians regard the economical uses to which their embalmed bodies were appropriated a few centuries ago! In the words of Ambrose Paré, the great surgeon of five French kings in the sixteenth century, is a full account of the preparation and administration of "mummie,"—that is, Egyptian mummies, powdered and made into pills and potions,—"to such as have falne from high places or have beene otherwise bruised." The learned physician enters his protest against the use of it, (which he says is almost universal with the faculty,) as quite inefficacious and disgusting. His disgust, however, arises principally from the fact that the "mummie" prepared by the apothecaries must have been derived "from the carcases of the basest people of Egypt; for the nobelmen and cheefe of the province, so religiously addicted to the monuments of their ancestors, would never suffer the bodyes of their friends and kindred to be transported hither for filthy gaine and detested use."

If such traffic be base, what shall we say of some priests of Nicaragua, who renovate their burial-grounds by exhuming the bones of the dead, with the earth that surrounds them, and selling the mass to the manufacturers of nitre? No sentiment of reverence for the sepulchres of their fathers incites them to resist the inroads of foreign pirates,—for they manufacture their fathers' bones into gunpowder.