active 1894-1902 A. Anderson

“ A gas is, you may have already guessed, simply a fluid. Matter exists in three states, solid, liquid and gaseous. Everything can exist in these three states under different conditions of heat and pressure.
For instance, ice, water, and steam are precisely the same thing, a mixture of oxygen and hydrogen, though in different states. Hence steam is simply the gaseous form [58] of ice or water. Now some gases are heavier than air, and among them is carbonic acid, a gas given off from the lungs in breathing. ”

“ Remove the spoon from the flame, when the liquid will become a solid of a brilliant emerald green color, and so remain until its heat sinks nearly to that of boiling water, when suddenly a commotion will take place throughout the mass, beginning from the surface, and each atom, as if animated, will start up and separate itself from the rest, till in a few moments the whole will become a heap of powder. ”

“ Yet what boy can look on the brilliantly colored fires of a Fourth of July display, or the burnished gold of the setting sun, or the fantastic pictures in the glowing coals in a grate, and not feel that there is still something of magic and mystery in fire still? What the boy feels, the scientist cannot explain. ”

“ Also, carbonic acid gas is given off by the lungs. It may seem curious, but it is none the less true, that breathing is a process of combustion. The blood brings to the surface of the lungs the carbon, which has resulted from the waste of the internal organs of the body. When drawing in a breath the oxygen present in the atmosphere meets the impure blood at the surface of the lungs, and purifies it by uniting with the carbon in it. Then, though oxygen has been breathed in, carbonic acid gas has been breathed out. ”

“ The phosphorus may be placed in a small copper cup, with a long handle of thick wire passing through a hole in a cork that fits the jar. The phosphorus must first be ignited; and as soon as it is introduced into the oxygen, it gives out a light so brilliant that no eye can bear it, and the whole jar appears filled with an intensely luminous atmosphere. It is well to dilute the oxygen with about one-fourth part of common air, to moderate the intense heat, which is nearly certain to break the jar if pure oxygen is used. ”

“ One great fact must be remembered, which is at the very root of chemistry. Nothing is really lost, however much its form may be changed, or however many changes it may pass through. For instance, it may seem that when a block of wood be burned that a very large amount of it is lost. If, however, the ashes, the smoke, and the carbon that is burned by the air be all weighed, the result would be exactly the same as the weight of the original block of wood. ”

“ If only consisting of nitrogen, the human race would also die, because this element is incapable of supporting life; people would be suffocated, in fact.
Therefore, a judicious mixture of the two is essential to the life of animals. Generally, in a hundred parts of air by weight there are seventy-six parts of nitrogen to twenty-three of oxygen.
Besides these two gases, there is also a quantity of carbonic acid gas in the air, given off by all the fires and animals in the world. Of course, its amount is much greater in the great towns and manufacturing centers than in country districts. ”

“ Water being a colorous fluid ought, one would imagine when mixed with other substances of no decided color, to produce a colorless compound. Nevertheless, it is to water only that blue vitriol or sulphate of copper owes its vivid blueness, as will be plainly evinced by the following simple experiment. Heat a few crystals of the vitriol in a fire-shovel, pulverize them, and the powder will be of a dull and dirty white appearance. Pour a little water upon this [44] when a slight hissing noise will be heard, and at the same moment the blue color will instantly reappear. ”

“ Charcoal is pure carbon in the uncrystallized state, which the magic of crystallization has transformed into the symbol of all that is brilliant and beautiful.
Beauties of Crystallization.
Dissolve alum in hot water until no more can be dissolved in it; place in it a smooth glass rod and a stick of the same size. Next day the stick will be found covered with crystals, but the glass rod will be free from them. In this case the crystals cling to the rough surface of the stick, but have no hold upon the smooth surface of the glass rod. ”

“ To show that oxygen is necessary for the support of combustion, fix two or three pieces of wax taper on flat pieces of cork, and set them floating on water in a soup-plate, light them, and invert over them a glass jar.
As they burn, the heat produced may perhaps at first expand the air, so as to force a small quantity out of the jar, but the water will soon rise in the jar, and continue to do so until the tapers expire, when you will find that a considerable portion of the air has disappeared, and what remains will no longer support flame. ”

“ An experiment to prove that the atmosphere does consist of nitrogen and oxygen, may be prettily proved in the following simple manner: A glass marmalade jar, or a soup-plate filled with water, and a piece of phosphorus as large as a pea, are the only things necessary. Take very great care not to touch the phosphorus, for the heat of the hand is sufficient to set it on fire, and a terrible wound would be caused. ”

“ Fill a glass tumbler with water, throw upon its surface a few fragments or thin shavings of camphor, and they will instantly begin to move, and acquire a motion both progressive and rotary, which will continue for a considerable time. During these rotations if the water be touched by any substance which is at all greasy, the floating particles will quickly dart back, and, as if by a stroke of magic, be instantly deprived of their motion and vivacity. ”

“ It is an interesting and amusing experiment to inflate a [64] balloon made of gold-beater’s skin (using a little gum arabic to close any holes or fissures) , filling it from a bladder or jar, and tying a thread around the mouth of it, to prevent the escape of the gas. When fully blown, attach a fanciful car of colored paper, or very thin pasteboard, to it, and let it float in a large room; it will soon gain the ceiling, where it will remain for any length of time; if it be let off in the open air it will soon ascend out of sight. ”

“ A gas flame is gas in a state of combustion, whereas the electric light is no example of it, although the wire within the glassen cylinder is red hot, and to all appearance burning. Combustion generally takes place through the strong affinity of some element, such as carbon in a substance for the oxygen in the atmosphere. In coal gas, for instance, the carbon contained in it unites with the oxygen in the air to form a colorless substance called carbonic acid gas. ”

“ As you rise higher and higher the weight of the air is less felt, and this makes people so uncomfortable that at a height of about 9,000 or 10,000 yards the liquids in our body—the blood, the water, the bile—tend to escape outwards. Why? Because they are no longer balanced by an outside pressure equal in force to them. In fact, if you continued to ascend, your fate would be that of the bladder in the first experiment—you would burst. ”

“ If the pressure ceases the big tube, on account of its own elasticity, takes its former form and sucks in the air. This time it is the valve at B which is lifted and lets pass the air which fills the body of the pump. If one has fixed on to the fitting at B, the long india-rubber tube No. 3, which is plunged in a receiver—a receiver is any vessel in which the air is exhausted, or into which it is forced—it is easily understood [18] that after a few moves of the pedal, the air is drawn out, and a vacuum is obtained. ”

“ When the copper is no longer coated, but remains clean and bright when immersed in the fluid, all the silver has been deposited, and the glass now contains a solution of copper.
Nearly all the colors used in the arts are produced by metals and their combinations; indeed, one is named chromium, from a Greek word signifying color, on account of the beautiful tints obtained from its various combinations with oxygen and the other metals. ”

“ This heat is produced by the energetic action of the tin on the nitrate of copper, taking away its oxygen in order to unite with the nitric acid, for which, as well as for the oxygen the tin has a much greater affinity than the copper has.
Combustion without flame may be shown in a very elegant and agreeable manner, by taking a coil of platinum wire and twisting it round the stem of a tobacco pipe, or any cylindrical body for a dozen times or so, leaving about an inch straight, which should be inserted into the wick of a spirit lamp. ”

“ As soon as the acid touches the salt the latter is decomposed, and liberates a gas which ignites the phosphorus, producing much the same appearance as in the last experiment.
Into the half of a broken phial put some chlorate of potash, and pour in some oil of vitriol. The phial will soon be filled with a heavy gas of a deep yellow color. Tie a small test tube at right angles to the end of a stick not less than a yard long, put a little ether into the tube, and pour it gently into the phial of gas, when an instantaneous explosion will take place, and the ether will be set on fire. ”

“ Many animal and vegetable substances, consist, for the most part, of carbon, or charcoal, united with oxygen and hydrogen, which remember, together combined, form water. Now oil of vitriol or strong sulphuric acid, has so powerful an affinity or so great a thirst for water, that it will abstract it from almost any body in which it exists. ”

“ These gases are oxygen and hydrogen. Every atom of water consists of one part of the former gas and two parts by volume of the latter. This you may prove in the following way:
Buy a piece of sodium, a metal that must not be touched with the fingers, and thrust it into a small one-ounce jar half full of water; cork the jar tightly.
Through a hole in the cork pass a glass tube, the outer end being drawn in a flame to a fine point. Apply a light at the end of the tube. The escaping gas will catch fire and burn with a light blue flame. This gas is hydrogen. ”