WATER AND THE METALS
The effect of lead on man is remarkable. It is a poison and its action is to cause the bones and arteries to harden. It is as though it were to make a man as old as the hills and indeed of all the metals it stands nearest to the grave. From the cosmos, it has sunk deepest into the earth. Sad, sombre and immensely heavy, it is yet of little value, for it is not noble.
In contrast, silver shines brightly and is an excellent mirror. Most of the mirrors we use today are made of silver, though in the old days mercury was generally used. Lead is dark and blackish grey while silver is white and shining, especially when it has been newly won. When silver ore is being smelted, it gathers in the bottom of the crucible and gives forth a bright light, the ” silver-glint,” which can be demonstrated. One cannot help feeling how silver is bound up with the power of light. Its light reminds one of the moon and the moon too is a mirror for it reflects the sun’s light. Silver has precisely the opposite effect on man to the effect of lead. It is used in feverish conditions and has a powerful effect on inflammations. It does not harden man, nor make him old. It is still quite young and shines as though it had just come down out of the universe. A noble metal quite different from lead.
And now we turn to a second pair of antithetical metals; mercury and tin. Tin is brittle, and when you bend a stick of solder, it grinds and grates. This sound is called the ” cry of tin.” Tin is not so unsightly as lead, nor is it so heavy. Objects made of tin are very durable, for tin is quite a noble metal. Only great cold will make tinware flake away and crumble to dust.
The most remarkable thing about mercury is that it is liquid. While tin is full of internal angles and corners, which creak and grind, mercury readily divides into round drops which quickly gather together again and are lost. While tin is jagged and angular, mercury is round and mobile, like a round wave.
The fluidity of mercury is a constant source of wonder to children, as is the way in which it escapes in all directions when the hand is plunged into it in an endeavour to grasp it. Here mention can be made of the fact that at one time all the metals were as fluid as mercury. This was the case when the earth as a whole was still fluid, but mercury is the only one which has remained a fluid until the present time. That is why we are so amazed to find that a metal can be like water. But in some ways it is markedly different from water. If two tubes are filled—one with water and one with mercury, it is found that the former has a concave surface and the latter a convex surface. Compared with the weight of an equal volume of water, the mercury is surprisingly heavy. When you spill it, water makes everything it touches wet, while mercury breaks up into little drops which presently coalesce leaving everything dry. Mercury and water are almost the only natural fluids on earth.
Mercury is the fluid of an earlier age. Unlike our water of today, this ” water ” of an older age is still preserved in fine drops in the interior of the earth. It can also be won from ores. The fine drops are called ” Virgin quick-silver.” The children are now told that mercury is capable of dissolving silver and gold and indeed nearly every metal except iron. When this so- called amalgam is heated, the mercury passes off as vapour, it becomes air and is presently deposited all around as a fine rain of tiny drops of mercury, while the gold or the silver is left behind in the crucible. Again we see the likeness to water. Just as salts can be dissolved in water, so can most metals be dissolved in mercury, returning in this way to their liquid state. Like water, mercury is mobile and reconciles the greatest contradictions. The alchemists, or chemists of medieval days, called it ” servus fugitivus ” the volatile servant, because it may be driven off again after gold has been dissolved in it. The gold or silver may be recovered, just as salt or anything else dissolved in water may be recovered by evaporation. Thus we make both water and mercury into our servants, who we may dismiss at will. In former times the qualities one associates with mobile drops were known as ” Mercurial ” qualities.
In like manner, copper and iron may now be contrasted. The red colour and malleable nature of copper are first pointed out. A thread of copper can be drawn out to extreme fineness. When blended with tin, copper gives us bronze. It thus becomes harder and suitable for a great variety of uses. Before men had learnt how to use iron, they made weapons of bronze. It is the bronze in bells which gives them their beautiful tone. Copper turns black in fire. When exposed to the air for some time it turns green—the well known ” patina.” Dissolved in acid, it turns blue. It can thus assume a variety of colours. There is something mild, soft and colourful about copper. Its beauty, softness and flexibility are remarkable.
Iron is grey, almost black, but it has nevertheless a metallic shimmer. It rusts when exposed to air, especially in the presence of water. The colours of iron ores and salts tend toward red. Iron is present in our blood and without it we could not breathe. Weapons and railways and the whole world of machinery are made from iron. The terrific heat of the blast furnace, alone makes it possible to win iron. Steel is made from iron. There is about it something hard, powerful, and downright warlike. It permeates the whole earth, which contains more of it than of any other metal. In many respects it is the opposite of copper. Copper is red and turns black in the fire. Iron is black and becomes red in the air. Iron ores are usually reddish while copper ores are blue-green.