Chapter II: What May Be Seen Upon the Earth (1)

"I care not, Fortune, what you me deny;
You cannot rob me of free Nature's grace;
You cannot shut the windows of the sky
Through which Aurora shows her bright'ning face;
You cannot bar my constant feet to trace
The woods and lawns by living streams at eve."

Of all the strata composing our planetary mass, the most important, so far as man is concerned, is, at the same time, the most superficial; for it is here that all the phenomena of life transpire. Our vegetable earth is the great laboratory in which are prepared all the solid, liquid, and gaseous aliments necessary for the nourishment of animal life. It is on the surface of the globe that men play their various parts. And why? Can it be for no other purpose than to modify, in some degree, its aspect, that they occupy the terrestrial surface? One would be tempted to think so on consulting what these majestic _bimanes_ pompously designate their "Universal History." Regions formerly blooming with fertility,--gay with gardens, and orchards, and meadows,--musical with brooks, and glorious with harvest,--are now uncultivated and barren. Monuments which seemed adapted to defy the winds and the rains, and the corroding touch of the years, lie shattered in ruins; and with them the once populous cities and the once mighty empires of which they were the pride. The jackal howls among the broken columns of Tadmor; the sand-drifts have accumulated above the splendour of Memphis and Thebes. With their stones other monuments are raised, other cities are embellished, and other empires, which, in their turn, undergo the same unalterable fate: a perpetual relation of human forms, in every respect comparable with that which transpires in the bosom of the prolific earth, our common mother and nurse.

But why do men wander so far from the straight way? Why do they their best to ensure each other's unhappiness? They seem, alas! ignorant of the tendency of their actions, while attaching themselves to things transitory, and despising things imperishable. These, indeed, they would utterly ignore; they would live, like the brutes, unconscious of their destiny, if, at the bottom of their indestructible conscience, there did not prevail a glimmer of light, though more or less eclipsed, if they did not all feel themselves attracted, if they did not all irresistibly gravitate, some more quickly, others more slowly, towards the sun of eternal truth and justice. Instead of moving with sidelong sinuous pace, instead of taking ninety-nine steps backward for every one hundred taken in advance, they would all march onward in the way of progress; were it not that they pass their time in clipping their own wings; were it not that, to bend their heads the better--_Veluti pecora ventri obedientia_--they check the aspiring flight of that thought which would soar beyond the present; in a word, were it not that they lay a sacrilegious hand--unfortunate wretches!--on that which God Himself has respected in His creature--Liberty! The doubt which perplexes us as to the great problem of our destiny,--the doubt which allows so much latitude to the workings of our conscience,--does it not indicate the path we ought to follow? Should not men regard their freedom with peculiar reverence, when the Divinity they invoke has mercifully refrained from fettering it? Creatures of a day, who live as if you would never die! the contradictions and the miseries of which you so incessantly complain, are your own work. Help, help yourselves, by the development of your faculties, by the cultivation of your heart and mind, for herein you shall see the law and the prophets. Barren lip-service is nothing better than blasphemy!

* * * * *

But let us return to the ground which we tread, and where our life-companions are the animals and the plants.

* * * * *

The uppermost stratum of our globe undergoes the direct action of the light and heat of the all-vivifying "orb of day." This action, very unequal in its effects, and most important to understand, has scarcely been touched as yet by scientific research. Our geologists, having been more busily engaged with the inside than the outside of the earth, have broached certain plausible theories--for the most part of a very dubious character--respecting the central fire, Plutonism and Neptunism, the stratification of the planets, the formation of mountains, valleys, and basins. Our mineralogists, thinking far less of the chemical molecular constitution of the different formations than of their crystalline constitution, have minutely studied the physical qualities and geometrical forms of the integral parts of the rocks; but neither have condescended to direct their inquiries to the layer of soil trodden underneath their feet. Yet this very layer of arable earth, to which all bodies must return after death what they have taken from it during life,--this much despised _humus_, furnishes all our agricultural products, the very foundation and support of our material existence.

To touch industrial occupations--to meddle with trade, commerce, or agriculture--is unworthy of Science! Such is the silly cry of the many distinguished savants who pride themselves on what they call their "freedom from selfish considerations."

Be it so; but then you ought surely to be consistent, and never regard science as a profession or a bread-winner.

ON THE CHEMICAL ACTION OF LIGHT.

It is no easy study to investigate the modifications and chemical effects which the terrestrial surface is capable of receiving or undergoing, either from the direct rays of the sun, or from diffused light. It requires new methods of inquiry,--methods frequently of extreme delicacy, as the labours of Bunsen and Roscoe, of Kirchhofer and Tyndall, have abundantly demonstrated. Let us here confine ourselves to establishing the fact that the chemical action of light varies according to the geological constitution of the soil,--according to the diurnal and annual obliquity of the solar rays,--according to the hours of the day,--according to the latitudes and seasons. The maximum of effects is manifested about the times of the solstices.

For the better co-ordination of these phenomena, might we not, as has been done in regard to the distribution of heat over the terrestrial surface,[78] link together by lines the points of equality? We should thus create an aggregate of _iso-photo-chemical_ lines,--diurnal, mensual, and annual,--of incontestible utility for the progress of general physics and meteorology, which are still in their infancy.

But to realise this magnificent programme, the union and agreement is necessary of scientific men in every region of the globe; an ideal, therefore, as yet, is very far from being attained.

THE ACTION OF HEAT.

The earth is subject to the influence of two different sources of heat. One, like the arterial blood, strikes from the centre to the circumference: this internal heat it is which has been stored up since the unknown epoch when our globe was nothing more than an incandescent nucleus, surrounded by condensable vapours. The other, like the venous blood, flows from the circumference towards the centre: this is the solar heat which the earth continues to receive through its crust.

The first of these sources lies beyond the domain of experiment. It has been the object of numerous hypotheses and diverse speculations, with which we shall not here concern ourselves. The second source is alone accessible to our investigations, and yet the network of _isothermal lines_ is scarcely defined.

Since the year 1817, when Alexander von Humboldt conceived the felicitous idea of representing by lines the same mean temperatures enjoyed, in a given space of time, by the different regions of the globe, researches of this nature have very considerably multiplied. But these researches--do not forget--refer rather to the temperature of the atmosphere than to the heating of the inferior stratum of that gaseous ocean whose bed or foundation is the terrestrial crust. And it is the penetration of the latter by the sun's calorific rays which we would especially desire to understand. Here, then, a sufficient margin is left for our curiosity.

"If the king, my father, does not rest from his conquests," cried Alexander of Macedon, while still a child, "he will leave me nothing to do when I shall have reached manhood." To such a complaint, be you sure, dear reader, that the conquests made by science will never give rise. Every step in advance is but a step into the infinite: what we have done only shows us the boundless extent of what we have to do.

It is this reflection which must always teach humility to the scientific student, even while he rejoices in the achievements of human patience and genius. He will not despair for he knows that great victories have been won: he will not grow arrogant, for he knows that he is still on the threshold of eternal truth. As Sir J. Herschel has justly said:--"He who has seen obscurities, which appeared impenetrable, in physical and mathematical science, suddenly dispelled, and the most barren and unpromising fields of inquiry converted, as if by inspiration, into rich and inexhaustible springs of knowledge and power, on a simple change of our point of view, or by merely bringing them to bear on some principle which it never occurred before to try, will surely be the very last to acquiesce in any dispiriting prospects of either the present or the future destinies of mankind; while, on the other hand, the boundless views of intellectual and moral, as well as material relations, which open to him on all hands in the course of these pursuits,--the knowledge of the trivial place he occupies in the scale of creation, and the sense continually pressed upon him of his own weakness and incapacity to suspend or modify the slightest movement of the vast machinery he sees in action around him, must effectually convince him that humility of pretension, no less than confidence of hope, is what best becomes his character."[79]

The temperature of the terrestrial surface perpetually varies under the influence of local as well as general causes. Had this fact been known to the philosophers of antiquity, they would have taken advantage of it to liken the earth to an animal whose skin is more or less sensible of heat, not only according to the difference of the seasons, but according to the different hours of the day.

The diurnal thermometrical variations are those which penetrate the least profoundly into the interior of the soil. At a depth of about five feet they cease to be perceptible. The maxima and minima of the year, however, can be detected at a sufficiently considerable depth. The limit descends as low as 80 to 100 feet. Below 100 feet, the terrestrial stratum is found invariable,--that is, inaccessible to the thermometrical changes of the atmosphere. It is remarkable that the temperature of this stratum differs but little from the mean annual temperature of the air, which, in the latitude of London, is 49°.

* * * * *

The maxima and minima of the yearly heat are propagated very slowly in the earth, and their difference gradually becomes less and less. Thermometers buried 26 feet deep in the ground, mark, in our latitudes, the maximum of temperature only on the 10th of December, and the minimum on the 15th of June. But there are certain elements which we must take into account. Thus, the depth of the invariable thermometrical curve depends both on the latitude of the place, on the conductibility of the strata, and the difference between the highest and lowest temperature of the year. The less this difference, the more nearly does the invariable stratum approach the surface. Here we have the reason why, in the intertropical torrid zone, where the temperature scarcely varies above two or three degrees in the whole year, the invariable curve is not found more than forty centimetres beneath the surface.

* * * * *

In the temperate zone, lying between the torrid and the frigid zones, the same phenomena assume, apparently, a more complex character; the isogeothermal lines inflect as diversely as the isothermal, and the former are far from running parallel with the latter. And this is easily understood, even without any experiment, for there is no relation between the ever-varied composition of the terrestrial strata, and the much more uniform composition of the atmosphere.

In the frigid zone, the soil remains constantly frozen for an insignificant depth, whatever may be the temperature of the encircling atmosphere. In some regions a stratum of ice and snow eternally reposes on the surface of the soil.

Unfortunately the observations, which require to be undertaken on an uniform plan and under well-weighed conditions, at various points over the whole globe, are as yet far too few to assist us in defining any general currents of heat or cold, whether variable or constant, as prevailing in the lower strata of the gaseous ocean of our planet.

ARABLE LAND.

A more useful picture than that of the isogeothermal lines would be one of all the arable land covering the continents of the Old World and the New,--indicating the composition of this nutritive earth, the nature of the soil on which it reposes, as well as the various kinds of cultivation appropriate in different climates. Here is a work to be achieved,--a work which would benefit the whole human race,--a work differing vastly from the conquests and achievements of too many of those "heroes" the world delights to honour.

"Peace hath her victories
More renowned than war."

In this immense task, of which, as yet, not even the outlines have been sketched, particular attention would require to be paid to the _subsoil_; for upon this the success of all cultivation literally depends.

Arable land is the most superficial stratum of the cultivable terrestrial crust; it is this which the plough turns up and subdues; it is this which, properly manured, and enriched by the decomposition of organic matter, furnishes to vegetables their principal nourishment. As it varies in thickness, it necessarily presents one or other of the following circumstances:--1st, The labourer, penetrating the entire stratum of arable earth (Fig. 69, _a_), will strike down to the subsoil (Fig. 69, _b_); or, 2d, he will not traverse the entire stratum (Fig. 69, _c_); or, 3d, after having traversed the entire depth of the humus, he will reach a portion of the subsoil (Fig. 69, _d_); or, 4th, after having gone through both humus and subsoil, he will discover another layer of arable earth, which may be either pure humus, in a thick inclined stratum (Fig. 69, _e_), or humus mixed with the débris of the subsoil.

As for the subsoil, it may, by its composition, completely modify, stimulate, or delay the action of the vegetable mould, however rich this may be in assimilating principles. Thus, where the subsoil is argillaceous, the pluvial waters are arrested by it as by a bed of impervious cement, and render the ground too damp and cold to yield abundant harvests. In such a case subsoil-drainage is the best remedy. But if the earth be porous, the moisture gradually percolates through its various layers, fertilising and warming, communicating to the plants the needful humidity, and assisting in the production of that most glorious of all the scenes of cultivated nature--a corn-field thickly ripe with golden grain. In the poet's "Palace of Art" no finer picture can be seen than this:

"The reapers at their sultry toil.
In front they bind the sheaves. Behind
Are realms of upland, prodigal in oil,
And hoary to the wind."

Oh! a sight to thank God for, and rejoice in, is the field all aglow with the splendour of the harvest!

Without having recourse to chemical analysis, which is within the reach of a very limited number of persons, _clayey_ soils may be distinguished by the vegetable species that most commonly flourish in them: as--

I. _Plants belonging to clayey soils._--The Queen of the
Meadows, _Spiræa ulmaria_ (order _Rosaceæ_). Wild Angelica,
_Angelica sylvestris_. Common Sorrel, _Rumex acetosa_ (order
_Polygonaceæ_), and various kinds of Ranunculaceæ, as _Ranunculus
lingua_, _Ranunculus flamma_, and _Ranunculus sceleratus_.

II. _Plants belonging to sandy soils._--Horny Lotus, _Lotus
corniculatus_ (order _Rhamnaceæ_). Little Harebell, _Campanula
rotundifolia_ (order _Campanulaceæ_). Eyebright, _Euphrasia
officinalis_ (order _Scrophulariaceæ_). _Anthoxanthum odoratum._

III. _Plants belonging to argilo-calcareous soils._--Coltsfoot,
_Tussilago farfara_ (order _Compositæ_). Wild Mustard, _Sinapis
arvensis_ (order _Cruciferæ_). Buckwheat, _Polygonum aviculare_
(order _Polygonaceæ_).

IV. _Plants belonging to a sandy and calcareous soil._--Broom,
_Genista scoparia_ (order _Leguminosæ_). Centaury, _Centaurea
nigra_ (order _Gentianaceæ_). _Galium verum_ (order _Rubiaceæ_).
The Jacobea, _Seneecio Jacobæa_.

V. _Plants belonging to alluvial and marshy soils._--Reed,
_Arundo phragmites_, _Poa aquatica_, _Poa fluitans_. Rush,
_Juncus conglomeratus_ (order _Juncaceæ_).

After these different soils have been brought under cultivation, the characteristic species, which we have just enumerated, disappear, and are replaced by other plants, which grow, to all appearance, spontaneously, under the name of _weeds_; but, in reality, spring from germs or seeds too frequently mixed up with the different manures, or spread abroad by the agency of birds or the wind.

In reference to this latter consideration, the diffusion of plants, we shall transcribe an interesting passage from Balfour's excellent "Manual of Botany."

"Some plants," he remarks, "are disseminated generally over the globe, while others are confined within narrow limits. Some of the common weeds in Britain, such as chickweed, shepherd's purse, and groundsel, are found at the southern extremity of South America. _Laura minor_ and _trisulca_, _Convolvulus sepium_, _Phragmites communis_, _Cedium Mariscus_, _Scirpus lacustris_, _Juncus effusus_, and _Solanum nigrum_, are said to be common to Great Britain and New Holland. _Nasturtium officinale_, and _Samolus Valerandi_ are very extensively diffused, and they may be reckoned true cosmopolites. They are both natives of Europe, and they occur, the former near Rio Janeiro, the latter at St Vincent. _The lower the degree of development, the greater seems to be the range._ Some cryptogamic plants, as _Lecanora subfusca_, are found all over the globe.

"Man has been instrumental in widely distributing culinary vegetables, such as the potato, and the cereal grains, as well as many other plants useful for food and manufacture. Corn plants, such as barley, oats, rye, wheat, spelt, rice, maize, and millet, are so generally cultivated over the globe, that almost all trace is lost of their native country. They can arrive at perfection in a great variety of circumstances, and they have thus probably a wider geographical range than any other kind of plants.

"As regards these plants, the globe may be divided into _five_ grand regions--the region of _rice_, which may be said to support the greatest number of the human race; the region of _maize_; of _wheat_; of _rye_; and lastly, of _barley_ and _oats_. The first three are the most extensive, and maize has the greatest range of temperature.

"The grains extending farthest north in Europe are barley and oats. Rye is the next, and is the prevailing grain in Sweden and Norway, and all the lands bordering on the Baltic, the North of Germany, and part of Siberia. Wheat follows rye; it is cultivated in the middle and South of France, England, part of Scotland, part of Germany, Hungary, Crimea, and the Caucasus. We next come to a district where wheat still abounds, but no longer exclusively furnishes bread,--rice and maize becoming frequent. To this zone belong Portugal, Spain, part of France, Italy, and Greece, Persia, Northern India, Arabia, Egypt, the Canary Islands, &c. Wheat can be reared wherever the mean temperature of the whole year is not under 37° or 39° F., and the mean summer heat, for a period of at least three or four months, is above 55°. It succeeds best on the limits of the sub-tropical region. In the Scandinavian peninsula, the cultivation of barley extends to 70° N. latitude, rye to 67°, and oats to 65°. The cultivation of rice prevails in Eastern and Southern Asia, and it is a common article of subsistence in various countries bordering on the Mediterranean. Maize succeeds best in the hottest and dampest parts of tropical climates. It may be reared as far as 40° N. and S. latitude on the American continent, on the western side; while in Europe it can grow even to 50° or 52° of latitude. It is now cultivated in all regions in the tropical and temperate zones which are colonised by Europeans. Millet of different kinds is met with in the hottest parts of Africa, in the South of Europe, in Asia Minor, and in the East Indies."[80]

Professor Houston furnishes the following table in illustration of the distribution of _wheat_ and _barley_. It also shows the mean temperature which they require:--

BARLEY.

Winter Summer Annual
Mean. Mean. Mean.
N. Lat. 62-1/2° Faroe, 39° 51° 45°
70 Lapland, 22 46 33
67·30' Russia, 9 46 32
57·30' Siberia, 0 60 32

WHEAT.

Winter Summer Annual
Mean. Mean. Mean.

Lat. 58° Scotland, 36° 57° 64°
Norway, 23 59 39
Sweden, 23 59 39
Russia, 15 60 37
30° Cairo, 57 88 72
Macao, 64 82 73
Rio Janeiro, 68 78 74
Havannah, 71 82 77
Bourbon, 71 80 77

"Winds, water, and animals, are also instrumental in disseminating plants. Many seeds, with winged and feathery appendages, are easily wafted about; others are carried by rivers and streams, and some can be transported by the ocean currents to a great distance, with their generating powers unimpaired."

MUSHROOMS OR AGARICS (_Order_ FUNGI).

Every year--principally in autumn--we are startled by hearing or reading of cases of poisoning by mushrooms. Erudite connoisseurs, however, who have profited by Dr Badham's book on "Esculent Fungi," do not suffer themselves to be intimidated by these sad narratives, though, unfortunately, they are frequently too well founded; because they know how to distinguish the good from the ill, the true from the false, the edible from the poisonous mushroom. But this security ought not to embolden the inexperienced amateur in risking his life for the sake of a delicacy. It is true, nevertheless, that we frequently see men's lives exposed for something less.

"Look, what a splendid mushroom I have discovered!" a lady said to me, the other day; a lady who knew something of flowers, but nothing of _cryptogams_. "Take care!" I replied, taking from her hand the supposed prize; "this is the false mushroom; and would suffice, if served up at your table, to poison yourself and all your guests."

I ought here to observe that my friend had narrowly escaped death two years before, through regaling herself with a dish of mushrooms of very dubious character. Among the symptoms which she experienced, and which she described with medical exactness, she particularly dwelt upon the cold sweats, accompanied by a sentiment of undefinable terror, which is nothing else than the dread of death: it was the special symptom of poisoning with an unwholesome fungus.

Let us endeavour to make ourselves better acquainted with this formidable enemy of epicures. You will have no difficulty in finding it in any warm, close season, but especially in spring and autumn. The toadstool thrives indifferently in the shade of all the forest trees, but seems to prefer the oak and birch to the pine and fir. A patch of soft greensward, at the foot of an old oak, and in the neighbourhood of a "brawling stream" or "tranquil pool," will generally be covered with fungi of this description. The numerous synonyms attaching to it show how greatly it has exercised the _classifying spirit_ of our naturalists. Some call it _Agaricus muscarius_, as if we should say "kill-fly mushroom;" others, changing only the specific designation, designate it _Agaricus pseudo-aurantiacus_,--which signifies, literally, "false orange," in allusion to the beautiful yellow colour of the _true_ aurantiacus. What is certain is, that our mushroom, which can kill men as well as flies, belongs to the genus _Agaric_, so numerous in species that it can be formed into a family, that of the _Agariceæ_. The Agarics, of which the esculent mushroom (_Agaricus edulis_) represents the type, are easily recognised by their more or less fleshy _pileus_, or cap, garnished underneath with _lamellæ_, or gills, which radiate from the centre to the circumference, when the pedicel is in the centre.

But some cryptogamists are unwilling to recognise the _orange mushrooms_ (_les oronges_), whether true or false, as Agarics. They place them in a separate genus, the genus _Amanita_, though without informing us where they found the name. Meanwhile, they justify the formation of the new genus by the presence of the white swelling, the _volva_, or wrapper, of the _mycelium_, or spawn, which entirely covers both the true and the false mushroom on its emergence from the earth. Each, then, is an _Amanita_. But now remark their specific difference. The true mushroom, as it develops, ruptures its ovoid wrapper, or volva, leaving the remains entirely at the base of the pedicel; while, in the false mushroom, the débris of the volva are formed, not only at the base of the pedicel, as in the real Agaric, but even upon the red surface of the pileus itself: these are the white irregular warts characteristic of the Amanita, but wholly wanting in the Agaricus. Thus, there are two Amanitas: the _Amanita muscaria_, or "fly agaric," and the _Amanita aurantiaca_, or, as the English botanists call it, _Agaricus Cæsareus_, the imperial mushroom.

This fanciful "study" in nomenclature has the advantage of initiating us into the most essential distinctive characters of the two species in question. However, a few additional details are necessary to complete our history.

THE FLY AGARIC, OR AMANITA MUSCARIA.

The species seems to have been expressly created to teach our gourmands the necessity of vigilance; that before enjoying a dainty they must first learn to distinguish, under penalty of death, the poisonous fungus from that which safely and pleasantly tickles the palate. The warning is useful, moreover, as showing that even sensualists are not wholly exempt from the law of work.

The _Amanita_, like most falsehoods, is pleasant to the sight. Its round pileus, of a beautiful orange-red colour, spotted with white warts, and lined with white gills, seems to invite your attention. (Fig. 73.) Strike it down with your stick; the lamellæ or gills underneath resemble the white leaves of a book. Its graceful stalk, ornamented on the upper part by a well-designed necklet, is bulbous in its lower portion; its flesh is dazzlingly white; in short, its entire appearance is attractive. Yet it is a traitor! You little know the depth of its wickedness. Mix a few shreds of its white flesh with a little milk; every fly which drinks of the mixture will, in a few seconds, fall dead, their swollen abdomen bearing testimony to the effect of the poison. And in many districts of Germany, particularly in Thuringia, the peasants make use of it to rid themselves of the swarms of flies which, towards the close of summer, infest their habitations. It is thus that man may frequently turn to his advantage those objects of nature which, at the first glance, appear injurious rather than useful.

Various experiments have been essayed to test the intoxicating influence of our _Amanita_. Bulliard, author of the "Histoire des Champignons de France," made two cats partake of it. Six hours afterwards, these animals, who are so tenacious of life, were dead.

Haller, in his "Histoire des Plantes Vénéneuses de la Suisse," says that "the _Agaricus muscarius_ (_Amanita muscaria_) cannot be eaten with impunity, six Lithuanians having died of it; and in Kamtschatka it has been known to excite deadly attacks of delirium, accompanied by so deep a despondency, that those who have eaten of it would fain fling themselves into the fire, or fall upon their knives or daggers." This, however, we take to be an exaggeration. The truth is, that in Kamtschatka it is used to produce intoxication; and such is its strength, it imparts an intoxicating property to the urine of those who swallow it. When the fungus itself is not at hand, the would-be drunkard frequently resorts to this nauseous potion.

The flesh of the _Amanita_ is not yellow. Yet Vicat speaks of poisonings produced by the _Yellow Amanita_. "I had much difficulty," says this physician, "in saving two families of Lausanne, poisoned through eating a very small quantity of mushrooms, which the father in the one case, and the mother in the other, had mistaken for _Agarici Cæsarei_, though they were both esteemed great connoisseurs, and especially in this species; nor had they been once deceived for upwards of thirty years, until they indulged themselves in this delicious but deceitful dish."

These poisonings could have been occasioned only by the _Amanita_. Some varieties exist, in which the under surface of the pileus is yellow, but the flesh is white. To one of these varieties Vicat's anecdote probably refers.

Thus, the _Amanita formosa_ of Persoon has pedicel, pileus, and warts of the pileus, of a citron yellow. It is but a variety of the _Amanita muscaria_.

The _Amanita umbrina_ of the same botanist (the _Agaricus pantherinus_ of De Candolle) has an olive-coloured pileus; its surface, like that of _Amanita muscaria_, is covered with white scales.

The _Amanita solitarius_ is distinguished by the size of its umbilical cap,--sometimes depressed in the centre,--which is furnished with a great number of white or pale brown scales; when fully developed, it measures from thirty to forty centimetres in diameter. The pedicel is bulbous, with a membranous ring, white as snow, clasped around it; at the base it is clothed in pellicles, the remains of its scaly volva. The flesh is firm, thick, and white. You rarely meet with more than two or three individuals in the same locality; hence its name of _solitarius_. Bulliard speaks of the flesh as good to eat, when cooked on a gridiron, and seasoned with fresh butter, salt, and pepper. It is possible. But as it is so easily confused with the poisonous species, the author of the "Histoire des Champignons" would have done better to prohibit its consumption, whether eatable or not.

We may now turn to the method adopted by Dr Vicat to save the lives of the two families at Lausanne, who, as we have seen, were poisoned by partaking of the _Amanita_:--

* * * * *

I dissolved, he says, six grains of tartar emetic in a litre of water, and from time to time administered a spoonful to my patients; moreover, I made them swallow floods of warm water, sweetened with a little honey,--that is, a large tea-spoonful of honey to a cupful of water.

I had much difficulty to get one of the sufferers, who was sixty years old, to swallow the first few spoonfuls. He was plunged into a lethargic insensibility differing in no respect from complete apoplexy; his teeth were closely set. Those whom I had ordered to administer the mixture had given it up, after several useless attempts; and in all probability the old man would have sunk, had I not had the patience to hold, for some hours, against his teeth the back of the blade of a small silver knife, so as to profit by the few moments when the teeth were a little less firmly clenched. I used some force to make the blade act as a wedge, and after a while opened up a passage to the handle, which, serving as a lever, forced the jaws sufficiently apart to admit the introduction of a spoonful of the emetic. It was not, however, until fully two hours had passed that the patient, having undoubtedly swallowed the necessary dose, began to vomit, with strenuous efforts and frightful cries. This was at midnight. Four in the morning arrived before, after numerous alternations of vomiting and profound lethargy, he began to speak, and then like a man in delirium. After the first vomit, which was inconsiderable, the convulsions of his whole body were so very violent as to require four men to hold him, while I continued to make use of my knife as at first. Nor did I desist until I was satisfied that his stomach had been sufficiently cleansed. After this, I applied two strong blisters to the back of his legs. As these acted, the purging subsided, and at the end of twenty-four hours it had passed away entirely, the invalid finding himself as well as could be expected after sustaining so severe a shock. The other patients, who were not in so much danger, experienced twitchings and tremblings in the face, which quite disfigured them; the brain seemed a blank; though awake, they felt as in a dream, and their visions were most frightful.

It is evident, from these particulars, that mushroom-poisoning specially affects the encephalic nervous system, and that the best remedies are emetics and antispasmodics. In our present ignorance of what are the poisonous principles in the _Amanita_, we can adopt no other method than a chemical neutralisation.

AGARICUS CÆSAREUS, OR IMPERIAL MUSHROOM.

In this mushroom, for which, as we have seen, the _Amanita_ is too frequently mistaken, the inside as well as the outside is yellow; the upper surface of the pileus, which is equally free from scales and warts, is, however, of a reddish yellow, like that of an orange (whence the popular French name, _la vrai oronge_); all the other parts are of a beautiful citron hue. This agaric exhales an agreeable odour, combined apparently of the scent of the vanilla and the truffle. It decomposes rapidly, and when in a state of advanced putridity, the fragrance I speak of is succeeded by--well, by a fearful stench! When young, and still completely covered with its wrapper or _volva_ (this, in the _Amanita_, is imperfect), it is very like a hen's egg which has been partly buried in the ground so as to expose only the larger end. It seems partial to solitude; more than four or five are seldom found in the same locality. Moreover, in autumn it affects the same habitats as the _Amanita_,--which is unfortunate.

It would seem that our imperial mushroom was specially appreciated by the ancients, and it is said that Nero pronounced it a dish fit for the gods. In this circumstance originated the scientific name which has now become popular, and which was first applied to it by the cryptogamist Fries, _Agaricus Cæsareus_.

* * * * *

The _Boletus_ of Pliny appears to have been our Agaricus, and not one of our _Boleti_, which are easily recognised by the numerous tubercular projections covering the under part of the pileus. In proof of this I would point out that the Roman naturalist, after speaking of the _Boleti_ as genuine delicacies, immediately inveighs against them as dangerously poisonous. He relates that it was with one of these, or rather with one of the false mushrooms so easily mistaken for the true, that Agrippina poisoned the Emperor Claudius, to secure the imperial crown for her son Nero.[81]

The virtues of the mushrooms have been sung by Juvenal and Martial. The latter accurately distinguishes the true from the false, when reproaching Cæcilianus with his gluttony.

"Ah, you are used to devour your _Boleti_ alone, in the face of your invited guests; eat then, the _Boletus_ which Claudius ate!"

"Dic mihi, quis furor est? Turba spectante vocata,
Solus boletos, Cæciliane, voras.
Quid dignum tanto tibi ventri, gulaque precabor?
Boletum, qualem Claudius edit, edas."[82]

The best known and most valuable species of Agarici may be briefly enumerated:--

_Agaricus campestris_, or _Common Mushroom_, found in nearly all
temperate regions: pileus convex, and white, with a tinge of
brown; thick set on the under side with dark brown gills; stem
firm and fleshy, and surrounded by a white membranous ring.

_Agaricus Cæsareus_, or _Imperial Mushroom_, the _Kaiserling_ of
the Germans, already described.

_Agaricus deliciosus_, or _Orange-milked Agaric_, found in
coverts of fir and juniper; pileus viscid, orange, and upwards of
four inches broad; gills and juice of a fine orange colour.

_Agaricus procerus_, or _Parasol Mushroom_, found in the shade of
trees, on meadows with a sandy soil; stem from eight to twelve
inches high, with a thick spongy ring; pileus bell-shaped, and
covered with brown scales.

_Agaricus Virgineus_, or _White Field Agaric_, found in rich
moist pastures; pileus whitish, and convex; gills of a light
chocolate shade; stem nearly two inches broad.

_Agaricus eburneus_, or _Ivory Mushroom_, found in beech woods;
grayish-yellow pileus; broad gills; stem long and scaly.

_Agaricus Georgii_, _St George's Agaric_, or _Whitecaps_, found
in moist pastures, and in the shelter of old barns, farmhouses,
and churches; flesh yellow; gills yellowish-white; pileus twelve
to eighteen inches broad; the least valuable of British species
of agaric, but useful in ketchup-making.

_Agaricus oreades_, _Fairy-ring Mushroom_, or _Scotch bonnets_,
found in meadows, where it grows in circles known as "fairy
rings;" pileus seldom exceeds an inch in diameter; stem solid,
tough, and fibrous, with a boss or _umbo_ in the centre, of a
light brown colour; the flesh white, and of a pleasant odour.

_Agaricus odorus_, _Anise Mushroom_, or _Sweet-scented Agaric_;
pileus slightly convex, about three inches broad, and with pale
gills; the scent like that of anise; stem strong, fleshy, but not
very tall.

_Agaricus formosus_, or _Smoky Mushroom_; so called from the
colour of the upper surface of the pileus; the stalk and gills of
a pale yellow; grows in fir woods.

_Agaricus primulus_, or _Mousseron_, grows in woods and pastures,
where the soil is sandy; pileus convex, yellow, about three or
four inches in diameter; gills change from white to flesh colour.

_How many Vegetable Species exist over the whole surface of the Globe?_

I will not do my readers the injustice to suppose that they are unacquainted with the writings of our greatest English poetess, Elizabeth Barrett Browning. They will not fail to have been attracted by the prodigal genius, the superabundant power, the exquisite imagery, the profound spirit of tenderness, the high, pure thoughts, which render almost every page such delightful reading. Successful as she was, however, in giving expression to the most subtle emotions and the intensest feeling, I think she was even happier in her descriptions of scenery. These are invariably aglow with life and colour, and have all the fidelity of Creswick with the imaginative insight of Turner. Turning over her "Aurora Leigh," the other day, I lighted on the following beautiful picture:--

"I flattered all the beauteous country round,
As poets use--the skies, the clouds, the fields,
The happy violets, hiding from the roads
The primroses run down to, carrying gold--
The tangled hedgerows, where the rows push out
Their tolerant horns and patient churning mouths
'Twixt dripping ash-boughs--hedgerows all alive
With birds, and gnats, and large white butterflies,
Which look as if the May-flower had caught life
And palpitated forth upon the wind:
Hills, vales, woods, netted in a silver mist;
Farms, granges, doubled up among the hills,
And cattle grazing in the watered vales,
And cottage chimneys smoking from the woods,
And cottage gardens smelling everywhere,
Confused with smell of orchards."

As I read this fine passage, the thought occurred to me, how many thousands there are who, in such a scene as it so vividly depicts, would see no beauty whatever, whose heart would not respond to it, whose sympathies would not be aroused by all its variety of outline and all its rich magnificence of colour! Yet not in so wide a landscape alone, but in the smallest nook,--in the little clump of elms by the side of the stream, in yonder grassy knoll rising straight up from the old churchyard, in the quiet angle of the green pasture-meadows,--there is a whole world of wonder and beauty for him who has eyes to see and a heart to feel! Look at the flowery bank which runs along the side of an English lane. Is it not crowded with objects of the rarest and purest interest? Count the many varieties of grasses which clothe it so abundantly, count the many species of flowers and herbs which adorn it with a grace beyond all human skill, and acknowledge that in itself it might supply the inquirer with matter for years of study and meditation.

Pursuing this train of thought, I was led to think of the number of genera and species into which the plant world is divided,--a remarkable proof, not only of the power and wisdom, but of the goodness of the Creator, of His desire to furnish man with inexhaustible sources of pleasure and entertainment; and finally, to put to myself the question, How many vegetable species exist over the whole surface of the globe? If this corner of a leafy English lane is so rich in variety, what must be the case with "the wide, wide world?"

I was now brought to see that a question so difficult could, like so many others, be usefully approached only by its _inferior limit_; in other words, that in the actual condition of botanical science, we can but affirm the number which certainly _exceeds_ the sum of the vegetable species scattered over the surface of our earth. To determine this total with mathematical accuracy, we should need to have explored the terrestrial crust, liquid and solid, land and water, from the bed of ocean to the line of perpetual snow, and from the equator to the poles. And as yet we are very far from having obtained so complete a possession of the planet which has been assigned as a dwelling-place to our poor humanity,--alas, more presumptuous than powerful!

* * * * *

The number of plants mentioned by Theophrastus, Dioscorides, and Pliny, whom we take to be the representatives of ancient botany, does not exceed five hundred species. How very few, compared with the presumable total! The Middle Ages added scarcely anything to the botanical researches of antiquity. It is only since the discovery of America that we have seen the domain of Flora extending itself in unexpected proportions. But we must come down to the epoch of Linnæus (the middle of the eighteenth century) before we can obtain an accurate list of species, scientifically classified. Murray's edition of the "_Specilegium_" of Linnæus contains two thousand and forty-two species, including the Cryptogams. Wildmore, in another edition of the same great work, raised the total to twenty thousand. And this was the point at which our botanists had arrived when the nineteenth century opened.

But it was not long before they perceived that all these estimates, large as they seemed, fell immeasurably short of the reality. In attempting to distribute the different species among the then known regions of the globe, Alexander von Humboldt arrived at a total of forty-four thousand species, Phanerogams and Cryptogams included. De Candolle extended the estimate to upwards of fifty-six thousand.

Let us divide, in fancy, the earth into two parts,--one which has been visited by travellers, and one which still remains to be explored. Can you determine which would present the larger area? The latter.

Thus we possess but a very imperfect knowledge of the luxuriant, the glowing vegetation of the tropical and sub-tropical regions of the New World, in spite of the labours of Bates, Agassiz, Wallace, and others. To the north of the equator, we know very little of the flora of Yucatan, Guatemala, Nicaragua, the isthmus of Panama, the Chaco of Antioquius, the province of Los Pastos. We are not much better acquainted with the vegetation of the countries south of the equator. What do we know of the manifold species flourishing in Paraguay, in the province of the Missions, in the immense wooded region between the Ucayali, the Rio de la Madeira, and the Tocantin, three affluents of the mighty river Amazon? We know scarcely anything.

Our ignorance increases if from America we pass to Africa. Nearly the whole interior of this continent, from 15° N. latitude to 20° S. latitude, is, botanically speaking, a blank to us. The same is the case with the greater portion of Central Asia. The floras of the south and south-east of Arabia are still sealed letters,--treasuries to which we have not found the key. As much may be said of the floras of the countries situated between the Thian-Schan, the Kuenlung, and the Himalaya, as well as of the floras of western China, and most of the trans-Gangetic countries. We know still less of the vegetation of the interior of Madagascar, Borneo, New Guinea, and the greater part of Australia. To conclude: we are probably not acquainted with more than one-fifth of the vegetable species which cover the surface of our globe.

There are regions, moreover, which we imagine will always lie outside of our sphere of investigation; such, for instance, are the Polar regions, properly so called. Undoubtedly, it is open to us to conjecture that the Poles--those two extremities of our axis of planetary rotation--are not the home of any form of life. But this is only a conjecture; we are even without an analogy for it; since we have found, as shown in an earlier chapter of the present volume, living beings, plants, and animals, among the snows of our loftiest mountains. Moreover, might not the auroras, whose maximum of intensity occurs exactly at the poles, render life possible in regions where we at present suppose it to be _im_possible? Conjecture for conjecture,--acknowledge that we here touch in both cases upon an element completely beyond our human power.

* * * * *

These, then, are the reasons why, at present, we can only venture upon defining the _lower_ limit, the _restricted_ number, above which we are unable to fix the total of vegetable species living on the surface of our planet.

The method to be adopted has been indicated by Alexander von Humboldt in his "Ansichten der Natur" ("Pictures of Nature"). His method consists in the comparison of the vegetable families whose numerical relations are _known_, with the number of species contained in our herbariums, or cultivated in our botanical gardens.

But here, at the outset, a difficulty confronts us. Does any relation exist between the classification of plants by natural families and by their geographical distribution?

To group plants according to their analogies of structure, we study them from an abstract point of view, and without any regard to the medium in which they flourish. The question grows complicated if we also take into consideration their characteristic conditions and their distribution over the terrestrial surface. Families are then split asunder, and the importance of our scientific classifications disappears.

The gathering together of a small number of species, represented by innumerable individuals, confined within the same area, may suffice to communicate to a landscape its characteristic physiognomy: as, for example, is the case with the Asiatic steppes, the _landes_ of Brittany, the moors of Scotland, the palm-groves and the clumps of Cactaceæ of tropical America. By the side of species which impress us by their _mass_--that is, by the frequent reproduction of the same individuals at an infinitesimal distance from one another--are placed those much more numerous species which are everywhere very thinly sown.

But do the plants themselves follow, from the equator to the poles, the same law of _decrease_ as obtains from the base to the summit of the loftiest equatorial mountains?

Under identical isothermal lines, is the ratio of families known and identified to the probable aggregate of Phanerogams the same, in the temperate zone, on either side of the equator?

What are the vegetable families which preponderate at the two extremes, represented by the torrid and the frigid zones?

Under the same geographical latitude, or between the same isothermal lines, are the Synantheræ, the Gramineæ, the Leguminosæ, the Labiatæ, the Cruciferæ, the Umbelliferæ, more numerous in the Old than in the New World?

What families, either through their mass of individuals or their number of species, take precedence of the other Phanerogams?

How many species of one and the same family belong to any particular country?

What groups or families are characteristic of each zone?

Is the present classification of genera and species in all respects what could be desired?

* * * * *

These are questions that require to be considered, and to some of them we shall presently attempt replies.

Herbariums, though their classification is too frequently imperfect, may furnish us with data of great utility. The great herbarium of Benjamin Delessert was estimated, after his death, to contain 86,000 species,--a total not widely differing from that which Lindley, in 1835, estimated as the probable aggregate of the vegetable species of the world.

Great in importance are botanic gardens. Loudon, in his _Hortus Britannicus_ (ed. 1832), places at 22,660 the number of Phanerogams cultivated in the gardens of the Bristol amateur botanists. With this number we must not confound the living species exhibited, in other counties, in gardens designed for the instruction of students, nor the grand total reared for a similar purpose at Kew. Kunth's enumeration, in 1861, of the plants at the Botanic Gardens at Berlin, one of the richest in Europe, amounted to upwards of 14,000 species, including 375 heaths. Among the Phanerogams were 1600 Synantheræ, 1150 Leguminosæ, 428 Labiatæ, 370 Umbelliferæ, 460 Orchidaceæ, 60 Palmaceæ, 600 Gramineæ and Cyperaceæ, &c. By comparing these data with the number of species described in the works of De Candolle, Walpers, Bentham, Lindley, Kunth, and others, we find that in the Berlin gardens are cultivated only one-seventh of the known species of the Synantheræ, one-eighth of the Leguminosæ, one-ninth of the Gramineæ, and about one-fiftieth of the smaller families, such as the Labiatæ and Umbelliferæ.

* * * * *

Now, if we admit that, on the one hand, the number of phanerogamous species cultivated in all the great gardens of Europe is about 30,000, and, on the other, that the cultivated Phanerogams form about one-eighth part of the species described in books and preserved in herbariums, we obtain a total of 24,000 species.

But the Cryptogams, or Agams, such as heaths, mosses, lichens, mushrooms, fungi, mould, and the like, of which our knowledge, as yet, is very imperfect, are probably much more numerous in species than the Phanerogams; for these vegetables, mostly microscopical, develop themselves wherever life can manifest itself--on the barren and denuded rocks, as well as in the air and in the depths of the ocean. If we suppose that they exceed only by 2000 the estimated number of Phanerogams, we shall obtain a total of just half-a-million!

Such, in our opinion, is the number which approximatively represents the lower limit of the aggregate of vegetable species (phanerogamous and cryptogamous) inhabiting our planet. The innumerable individuals of this half-million of species are born, and live, and reproduce their kind, and die, like the twelve hundred millions of individuals of our solitary human species. The former, it is true, remain fixed to the soil which has witnessed their birth, while the latter wander, more or less freely over the terrestrial surface. Do not animals enjoy the same privilege of locomotion? Undoubtedly. But men boast of the reason and the conscience with which they are endowed. Agreed. But with the exception of a small number--the infinite minority of progress--to what advantage have men employed the reason and the conscience of which they boast?

* * * * *

But this is a digression. We proceed to place before the reader a few final data in illustration of the subject we have been considering--the number of existing vegetable species.

The following is an estimate of the known species of plants on the globe at different dates:--

Phanerogams. Cryptogams. Total.
According to Linnæus, 1753, 5,323 615 5,938
Pusoon, 1807, 19,949 6,000 25,949
Stendel, 1824, 39,684 10,765 50,649
Stendel, 1841, 78,000 13,000 91,000
Stendel, 1844, 80,000 15,000 95,000

The advance made of late years in the knowledge of existing species will be apparent from a consideration of Lindley's estimate in 1846:--

Genera. Species.
Thallogens, 939 8,394
Acrogens, 310 4,086
Rhizogens, 21 53
Endogens, 1,420 13,684
Dictyogens, 17 268
Gymnogens, 37 210
Exogens, 6,191 16,225
------ -------
Total, 8,935 92,920

According to Hinds, the following families are almost entirely restricted to particular divisions of the globe:--

_To Europe_--Globulariaceæ, Ceratophyllaceæ.

_To Asia_--Dipterocarpaceæ, Aquilariaceæ, Camelliaceæ,
Moringaceæ, Stilaginaceæ.

_To Africa_--Bruniaceæ, Brexiaceæ, Belvisiaceæ, Penæaceæ.

_To North America_--Sarraceniaceæ.

_To South America_--Rhizobolaceæ, Gillesiaceæ, Calyceraceæ,
Vochysiaceæ, Simarubaceæ, Monimiaceæ, Humiriaceæ, Papayaceæ,
Gesneraceæ, Lacistemaceæ.

_To Australasia_--Goodeniaceæ, Epacridaceæ, Stackhousiaceæ,
Brunoniaceæ, Tremandraceæ.

[A group of plants occurring only in one of the six great divisions of the world is called _monomic_, (from μονος _one_, and νομὸς, a _region_).

A group common to two divisions is _dinomic_; to three, _trinomic_; to four, _quatrinomic_; to all the divisions, _polynomic_.]

NATURAL FAMILIES PREDOMINANT IN THE NORTHERN HEMISPHERE.

Aceraceæ,
Alismaceæ,
Amentaceæ,
Artocarpeæ
(_fam._ Articaceæ),
Aurantiaceæ,
Berberaceæ,
Boraginaceæ,
Campanulaceæ,
Caprifoliaceæ,
Caryophyllaceæ,
Cistaceæ,
Coniferæ,
Cruciferæ,
Dipsacaceæ,
Elæagnaceæ,
Fumariaceæ,
Grossulariaceæ,
Hamamelidaceæ,
Hippocastaneæ
(_fam._ Sapindaceæ),
Hypericaceæ,
Magnoliaceæ,
Onagraceæ,
Orobanchaceæ,
Papaveraceæ,
Ranunculaceæ,
Residaceæ,
Rosaceæ,
Rutaceæ,
Saxifragaceæ,
Umbelliferæ,
Vacciniaceæ.

NATURAL FAMILIES PREDOMINANT IN THE SOUTHERN HEMISPHERE.

Amaryllidaceæ,
Atherospermaceæ,
Cactaceæ,
Capparidaceæ,
Crassulaceæ,
Dilleniaceæ,
Diosmeæ
(_fam._ Rutaceæ),
Geraniaceæ,
Hæmodoraceæ,
Heliotropeæ
(_fam._ Ehretiaceæ),
Iridaceæ,
Malpighiaceæ,
Melastomaceæ,
Mesembryaceæ,
Myoporineæ
(_fam._ Verbenaceæ),
Myrtaceæ,
Oxalidaceæ,
Pittosporaceæ,
Polygalaceæ,
Proteaceæ,
Restiaceæ,
Scævoleæ
(_fam._ Goodeniaceæ),
Spigeleæ
(_fam._ Loganiaceæ),
Stylidiaceæ.

THE HARVEST BUG.

"I very much wish," said my friend T. to me one day, "to buy a small estate in the vicinity of ---- Forest. If there should be one to sell, pray let me know of it."

It was not long before an opportunity arose for my friend to satisfy his desire. But after I had made him acquainted with it, he declared himself no longer willing to purchase a property in a district where, as he had learned, one was devoured by _red beasts_ all through the finest months of the year. What a frightful neighbourhood to live in, where you were forbidden to walk in your garden under pain of catching an itch in your legs!