Part 4
Clouds are amongst the most beautiful as well as useful things in nature, and it is one of the greatest proofs of the active benevolence of God, that all those things which serve man the most, are the most beautiful to contemplate. Without clouds there would be no rain, and without this no vegetation. In many parts of the tropical regions there is little or no rain, and in such parts desert places abound. Clouds are often of different states of electricity, and when they come near enough to each other, a transfer of the fluid takes place, accompanied with a flash of lightning (fig. 7) and a report, although this is not always heard at the same time that the lightning is seen, as sound does not travel nearly so fast as light; there is no danger from this kind of lightning. But it sometimes happens that a cloud in an opposite state of electricity to the surface of the earth is near enough to produce a flash of lightning between them, in this case it is extremely dangerous to be near; but when the thunder is not heard till some time after the flash is seen, there can be no danger, as it is then far away. Sound travels at about eleven hundred feet per second, therefore (in round numbers) it may be known that the lightning is one mile distant for every five seconds that elapse between the flash and the thunder. The notion which prevails that iron and steel attract lightning is entirely erroneous, they do not even conduct it so well as copper and many other metals.
Lightning conductors (fig. 8) are wires of iron or copper, made to project above the highest parts of buildings and carried down to the earth; they have the power of conducting the lightning down without injury to the building, for electricity (which lightning is) travels through metallic wires for any distance without disturbance or noise (as in the electric telegraph), but bad conductors are apt to be burst and rent by it if it be strong enough, creating flashes of light and reports. Lightning strikes most readily any projecting substance or point, the highest point is therefore selected for the protrusion of the upper part of conductors. In a plain or open space, trees and animals are often struck, as they form conductors (although very bad ones) to the lightning; being bad conductors, instead of allowing it to pass quietly to the earth as do the wires, they are generally destroyed by it. It has been often stated that we should select an open space in a thunder-storm, but this would render one liable to be struck, especially if there were no object near of larger dimensions, the best plan is to stand near to any trees or houses without touching them, the danger would not then be so great, the trees or buildings being taller, would be most liable to conduct the lightning to the earth. The danger of touching or leaning against a tree in a thunder-storm, arises from the person thus making himself (as it were) part of it and incurring the same risk.
Thunder-storms, which would at first thought appear to be of no utility to man, are indeed of great service; it is a common saying that thunder clears the air, this is the result of feeling and experience, but chemists have demonstrated the fact that a substance called "ozone" (a peculiar state of the element oxygen) is produced by thunder-storms; this ozone possesses the wonderful power of correcting (decomposing) putrid and unwholesome gases and exhalations which might otherwise produce fever, cholera, &c., it moreover destroys the ova or germs of many animals and vegetables which might otherwise be injurious to vegetation of more importance, the slight injury which these storms inflict here and there should weigh as nothing in the balance of utility with such universal good. Thus it is that the works of God have all the stamps of goodness, and this ought to inspire us with so much thankfulness as to overcome every fear for personal safety. Were these grand phenomena of nature, (as materialists would make us believe) the result of laws depending solely upon the physical co-operation of mere matter, good would be the exception instead of the rule, and most of them would produce effects, if not injurious at least not beneficial, but such is not the case, and throughout all the wonderful operations of nature there is not one but tends to good, for God often inflicts a small injury that a great good may result; we say a small injury, but it is questionable if the injury is not often a benefit, which appears to us injurious only because we do not understand it fully, every disturbing cause tends to produce some apparent disorder, such as storms, hurricanes, &c., some indeed so terrific as to destroy ships and houses, but what would be the result if the atmosphere were never disturbed from any cause? Why the lower stratum would become so loaded with impurities that it would be unfit to breathe, miasms and noxious gases would for ever remain a curse to the races of men and animals who might be doomed to inhabit such regions, but the very regions where these miasms are most likely to form are those about the tropics, and here it is that the greatest storms occur to remove them. Even the great deserts, which appear so useless to man, and which are uninhabitable to a great extent, have their office, and an important one too; they are to the earth what ventilators are to buildings, drawing the cold air from the poles to cool the regions that are too hot, and sending a current of heated air through the upper regions of the atmosphere (where it can do no injury to anything) to warm the colder parts of the earth, another instance of the wonderful care and goodness on the part of the Creator. The various and beautiful colours of the clouds, particularly at the rising and setting of the sun, are caused by refraction separating the white light into its primitive constituents, blue, red, and yellow light and their combinations, purple, orange, green, &c., and the more obliquely the rays impinge upon the earth the greater will be this refraction, this accounts for colours seldom appearing in the clouds at midday. But of all the beautiful effects of the refraction of light, the Rainbow (fig. 9) is the most glorious, it has been celebrated in all ages for its transient beauty. It is only seen when rain is falling in front of a brightly illuminated cloud, the sun being behind the spectator; it is a reflection of the sun by the cloud transmitted through millions of drops of rain, each of which acts as a prism, and produces rings of colour; for each of the rays of light (red, blue, and yellow) are refracted in unequal degrees, and therefore take separate places, forming the rings of colour seen in the rainbow.
The air is the great source from which all the nourishment of the organic creation, whether vegetable or animal, is derived; its carbonic acid is decomposed by the vegetables, which appropriate the carbon, turning over the oxygen to their companions, the animals; the ammonia of the air furnishes all the nitrogen of seeds and other nutritious parts of vegetables, which are eaten by animals; and water, the chief source of all nutriment, passes first from the air before it enters the soil, bringing both carbonic acid and ammonia to fertilise it. That all this nourishment is derived from the air is evidently shown by the formation and increase of mould in forests which have grown for centuries; this black mould is nearly all decayed vegetable matter, formed by the continuous fall and decay of leaves and trees, but which, instead of diminishing, increases. Now, where does all this come from? certainly not out of the earth, for it does not contain the necessary elements. Expose the surface of the bare earth for several centuries, and first small plants, then larger ones, will grow upon it, until the state of things described above takes place, the earth being just as rich in organic matter now as at the beginning, and much richer on the surface, where a thick stratum of black mould forms from the repeated fall and decay of leaves and wood; all the substance which the forest shall have drawn from the earth (with the exception of certain salts and earthy matters) must therefore have been derived from the air, which contains every ingredient necessary for its formation, while in the earth itself no kind of organic matter is ever found.
There was formerly a time when the carbonic acid of the air was in much greater abundance, and favoured the growth of those plants which thrive where there is plenty of water, as in swamps and marshes. They grew and decayed for a vast period of time, till a thick stratum of carbonaceous matter was deposited, which, after being buried (by some convulsion of nature) at a great depth, and pressed by the enormous weight of the superincumbent earth into a hard solid substance, is now being dug up by man, and forms that most valuable of all products of the mine, coal (fig. 10).
That coal is derived from decayed and altered vegetable matters, is pretty well proved; for many pieces of coal, if ground thin and subjected to the microscope, present a texture exactly such as can be seen in wood of the present date, and not only the ordinary structure, but in very many cases certain "dotted fibres," indicating that the wood belonged to the order of cone-bearing trees (_Coniferæ_), and there is but little doubt that the constant deposit of such wood and its slow and gradual decay was the real source of all our coal. How wonderful, and how good, is the foreknowledge of God! Just at a time when the great forests of the earth are fast disappearing, and with them the only other source of fuel for fires, this reserve of the old forests, which was then useless, serves man as a most excellent friend--more useful than gold or silver, more precious than diamonds or rubies! But this world is one of perpetual change, and the coal thus brought forth from the depths of the earth, is by man being rapidly restored to the air from whence--thousands of years ago--it was derived; and it is not coal alone which is thus being restored, but every organic being in the whole creation, for at their decay they all enter this vast mausoleum of the dead!
THE EARTH.
The Earth, considered as one of those spheres which circulate round the sun amidst the wide expanse of the firmanent, holds but an insignificant position among them, especially when compared with those great and magnificent orbs, Jupiter and Saturn; but, in another point of view, as the dwelling-place of all the animated beings, vegetables, and minerals, with which we have any practical knowledge, it holds to us a position in creation far above all the others.
It is upon the surface of this our earth that we behold in detail those wonders of the Great Creator's hands, which must fill all who contemplate and study them with enlarged ideas of His wisdom, goodness, and power. We see the millions of stars sparkling in the abyss of space, and our minds are so formed that we can measure and gauge their distances and rates of travelling, their orbits and their sizes, their weights, and the powers with which they attract and influence each other; but we only contemplate a star as one bright and beautiful object worthy to be one of the gems which the Almighty has set in His crown of glory, or a lamp to light the halls of His infinite habitation, but we still contemplate it as a single object; while on the surface of the earth our Maker has permitted us to roam and search out by what benevolent contrivances He has suited all things to the comfort and welfare of His creatures. How His mercy and goodness are extended amply to the most minute animalcule as well as to man, and how His powers of construction are to be found in the most minute objects which the microscope can display, as perfect as in the largest creature we behold. It is here upon our earth that we perceive how the structure and functions of all creatures are regulated and controlled by the unerring laws which He has created, over which laws the creatures have no control, and which if duly regarded and used according to the faculties each has been gifted with, will return the greatest joy and happiness their several natures are capable of, and secure all that perfection of operation which their mechanical frames are suited to perform; but before any description of the organised beings which dwell on the earth can be given, it will be proper to enter into a description of the earth itself, to see what sort of place God has provided for them, and how through succeeding cycles of time He has gradually perfected and prepared it for the reception of His last great work, Man.
It is only a few miles below the surface of the earth that man has been able to penetrate and examine, but reason comes to assist him where examination fails, and it would have been but a few hundred yards only that his labours could have extended had it not been that parts, which are generally situated miles below the surface, are occasionally found at or even raised above it, by some disturbing cause which operated in times far back; so that man is able to examine on the surface parts which he could scarcely dig down to.
The whole of the earth, its inhabitants, the air which surrounds it, the waters upon its surface, and its vegetable products, are composed of certain substances called elements, combined and united in certain numbers and proportions. The following is a list of all known:--
METALLIC ELEMENTS.
Aluminium 13.7 Antimony 12.9 Arsenic 75 Barium 68.5 Bismuth 21.3 Cadmium 56 Calcium 20 Cerium 47 Chromium 26.7 Cobalt 29.5 Copper 31.7 Didymium * Donarium * Erbium * Glucinium * Gold 197 Ilmenium * Iridium 99 Iron 28 Lanthanium * Lead 103.7 Lithium 6.5 Magnesium 12.2 Manganese 27.6 Mercury 100 Molybdenum 46 Nickel 29.6 Niobium * Norium * Osmium 99.6 Palladium 53.3 Pelopium * Platinum 98.7 Potassium 39.2 Rhodium 52.2 Ruthenium 52.2 Silicon 21.3 Silver 108.1 Sodium 23 Strontium 43.8 Tantalium 184 Tellurium 64.2 Terbinum * Thorium 59.6 Tin 59 Titanium 25 Tungsten 95 Uranium 60 Vanadium 68.6 Yttrium 32.2 Zinc 32.6 Zirconium 22.4
NON-METALLIC ELEMENTS.
Boron 10.9 Bromine 80 Carbon 6 Chlorine 35 Fluorine 18.9 Hydrogen 1 Iodine 127.1 Nitrogen 14 Oxygen 8 Phosphorus 32 Sulphur 16 Selenium 39.5
By this list it will be perceived that the greatest number of the elements are metals, but most of these are very rare and met with but in certain localities, making up but a very insignificant part of the earth's surface, while others (never found in nature, as metals) in combination with oxygen forming "earths" compose the greater part of its bulk. But of all the elements, oxygen (a gas) is the most widely diffused, and constitutes rather more than one half of the whole earth, thus it forms 1/5th of the air, 9/10ths of the water, of the various earths and rocks about 1/2, and in all organised beings about 3/4.
Of the metallic elements, those which form the greater bulk of the earth are--
Silicon. Aluminium. Calcium. Magnesium. Potassium. Sodium.
These never exist in nature as metals, but combined with oxygen forming the following earths and alkalies:--
Silica } Alumina } EARTHS. Lime } Magnesia }
Potassa } ALKALIES. Soda }
These four "earths" form about eighty-five per cent. of the whole bulk of this globe, the remainder being made up of water (composed of eight parts oxygen and one part hydrogen), of "salt," both as rock or crystal-salt, and dissolved in the water of the sea, of the ores of different metals (metals in union with oxygen, sulphur, &c.), and of the remains of former vegetation, existing as coal.
Silica is composed of 21.3 parts of silicon with 24 of oxygen, it is that earth which constitutes a great part of almost every soil, and forms sand, sandstone, and flint, it enters largely also into the formation of granite and the other primitive rocks; when pure it is called "quartz" or "rock-crystal" and is often found in large and beautiful masses. Silica, in different forms, contaminated and coloured by different metallic oxides, &c., forms that class of stones known as "agate," "Scotch pebble," "carnelian," &c., and in the form of flint is found nearly pure, forming "nodules" or rounded masses lying in layers in the chalk cliffs on our coasts, the origin of these nodules of flint is very obscure, but they are by many attributed to the petrifaction of sponges, &c., the general form of which they often retain as well as their internal structure, which may be seen when viewed in thin slices by means of the microscope. Pure silica is a white insoluble powder, and is much used by the makers of porcelain to mix with their other ingredients.
Alumina consists of 41.1 parts of aluminium in combination with 24 parts of oxygen, it is the earth which forms the basis of all clays, loams, and slates, it is in its pure state perfectly white but in most clays is coloured brown or blueish by oxide of iron, many of our most beautiful gems, as the ruby, sapphire, and emerald, consist chiefly of crystallised alumina coloured by oxide of iron, chromium, &c., this earth like silica enters largely into the composition of the primitive rocks.
Lime is another of the earths which form a great part of all soils; it consists of 20 parts calcium with 8 of oxygen. Unlike the two preceding earths, it exists only in union with some acid. When united to carbonic acid it forms limestone, chalk, marble, &c., and when in a crystallised state "Iceland spar." The various kinds of limestone are largely used as building-stones, and any of them when burnt yields lime or "quick-lime" as it is generally called, which is capable of uniting with a certain portion of water, giving out a considerable amount of heat during the combination. Lime is often found in union with sulphuric acid, forming gypsum or Plaster of Paris, in combination with phosphoric acid it forms the basis or earthy part of the bones of animals, and is found in some of the tissues of plants.
Potassa consists of 39.2 parts potassium in union with 8 oxygen, it constitutes about 12 per cent. of the granites and basalts (primitive rocks) in union with silica and alumina, it is also found in the fluids of many vegetables in union with carbonic, oxalic, and other acids.
Soda consists of twenty-three parts sodium with eight oxygen, it however does not exist in this form in nature, but in union with chlorine instead of oxygen, constituting chloride of sodium or common salt, this substance forms strata of considerable extent in some localities and being soluble has no doubt been washed out by the rains from many other places and has thus communicated saltness to the waters of the ocean. The other metallic elements exist chiefly in those forms of earth called "ores" being metals in union with oxygen, sulphur, &c., or are found in the metallic state, as gold, platinum, &c., it is from these ores that most of our useful metals are procured by the process called smelting, as in the case of iron, copper, lead, tin, &c. All the substances known result from the combinations of the elements, but these elements do not chemically combine in all proportions, but in certain definite quantities only; these quantities or proportions are signified by the numbers attached to each element in the list given,[1] and the union of these substances must be in the proportion of these numbers (or multiples of them) only, all superfluity of the substances combined remaining in a state of mere mechanical mixture. For example, if six parts of carbon (charcoal) made red-hot be plunged into a jar containing twenty parts of oxygen, it will unite with sixteen parts only of the oxygen (a multiple of eight), and form twenty-two parts of carbonic acid, the extra four parts of oxygen still remaining as oxygen mixed with the carbonic acid; and if into this carbonic acid twenty parts of lime be put, it will unite with the twenty-two of carbonic acid, forming forty-two of carbonate of lime, still leaving the four parts of oxygen untouched. Had forty parts of lime been put into the mixture, instead of twenty, still only forty-two of carbonate of lime would have been formed, and the other twenty parts (like the four of oxygen) being superfluous, would still have remained as lime, mixed with the carbonate of lime. These combining quantities are called the "equivalents" of the substances.
[Footnote 1: See the list of the elements at page 45; those which are distinguished by an asterisk, are elements of which the "equivalents" are not known.]
Upon examining various portions of the earth's surface, they will be found to differ in character from each other; in one place perhaps sandy soil will be found, in another, hard rock, in a third, clay, in a fourth, chalk, and so on. Now, if this examination were carried no further, it might well be presumed that each of these kinds of soil were continued downwards into the earth for an indefinite distance, but upon digging (as in sinking a shaft or well) it is found that the stratum of soil upon the surface is soon passed through, that others in succession present themselves and that this succession of strata is not a matter of chance, but (with certain restrictions) follows in invariable order. It is true some strata are occasionally not present, and that others replace them; but yet (taken altogether) there is the same order of succession everywhere found. The following diagram (fig. 1) gives the section of these strata from the earth's surface to the granite which is the lowest of all formations and through which no one has ever penetrated. The figures give an approximation to their average thickness in feet. These strata do not all run in a direction parallel to the surface of the earth, or else it would result that the surface would everywhere be made up of the highest, but they have been contorted and heaved up into mounds or depressed; and the granite has often been pushed upwards, carrying with it all the upper strata to a certain extent, at last thrusting quite through them all and presenting itself above the surface, forming in this way the tops of many very high mountains, Mont Blanc for instance. Such a mountain if cleft from the summit to the base would present a section similar to that shown in fig. 2, and thus it occurs (contrary to what would at first thought be supposed) that the highest ground is generally formed of the lowest strata, while the valleys are nearly always covered with the latest formations, which is partly owing to the elevating process before alluded to, and partly to the winds, rains, &c., tending to carry away and wash down every kind of soil from the upper ground and deposit it in the lower.