Faraday’s Prophetic Views.
“If we now conceive a change as far beyond vaporization as that is above fluidity, and then take into account the proportional increased extent of alteration as the changes arise, we shall perhaps, if we can form any conception at all, not fall short of radiant matter; and as in the last conversion many qualities were lost, so here also many more would disappear.
“It was the opinion of Newton, and of many other distinguished philosophers, that this conversion was possible, and continually going on in the processes of nature, and they found that the idea would bear without injury the applications of mathematical reasoning—as regards heat, for instance. If assumed, we must also assume the simplicity of matter; for it would follow that all the variety of substances with which we are acquainted could be converted into one of three kinds of radiant matter, which again may differ from each other only in the size of their particles or their form. The properties of known bodies would then be supposed to arise from the varied arrangements of their ultimate atoms, and belong to substances only as long as their compound nature existed; and thus variety of matter and variety of properties would be found co-essential.”[23]
[23] “Life and Letters of Faraday,” by Bence Jones. Vol. I, p. 216.
Three years later he returned to this theme in another lecture:—
“By the power of heat all solid bodies have been fused into fluids, and there are very few the conversion of which into gaseous forms is at all doubtful. In inverting the method, attempts have not been so successful. Many gases refuse to resign their form, and some fluids have not been frozen. If, however, we adopt means which depend on the rearrangement of particles, then these refractory instances disappear, and by combining substances together we can make them take the solid, fluid, or gaseous form at pleasure.
“In these observations on the changes of state, I have purposely avoided mentioning the radiant state of matter, being purely hypothetical, it would not have been just to the demonstrated parts of the science to weaken the force of their laws by connecting them with what is undecided. I may now, however, notice a progression in physical properties accompanying changes of form, and which is perhaps sufficient to induce, in the inventive and sanguine philosopher, a considerable belief in the association of the radiant form with the others in the set of changes I have mentioned.
“As we ascend from the solid to the fluid and gaseous states, physical properties diminish in number and variety, each state having some of those which belong to the preceding state. When solids are converted into fluids, all varieties of hardness and softness are necessarily lost. Crystalline and other shapes are destroyed. Opacity and color frequently give way to a colorless transparency, and a general mobility of particles is conferred.
“Passing onward to the gaseous state, still more of the evident characters of bodies are annihilated. The immense differences in their weights almost disappear; the remains of difference in color that were left, are lost. Transparency becomes universal, and they are all elastic. They now form but one set of substances, and the varieties of density, hardness, opacity, color, elasticity and form, which render the number of solids and fluids almost infinite, are now supplied by a few slight variations in weight, and some unimportant shades of color.
“To those, therefore, who admit the radiant form of matter, no difficulty exists in the simplicity of the properties it possesses, but rather an argument in their favor. These persons show you a gradual resignation of properties in the matter we can appreciate as the matter ascends in the scale of forms, and they would be surprised if that effect were to cease at the gaseous state. They point out the greater exertions which nature makes at each step of the change, and think that, consistently, it ought to be greatest at the passage from the gaseous to the radiant form.”[24]
[24] “Life and Letters of Faraday,” by Bence Jones. Vol. I, p. 307.
This remarkable deliverance recalls what another great experimental philosopher, Count Rumford, deduced as by dint of mechanical motion he melted ice in a closed and insulated receiver. He inferred that the heat thus generated was not a material substance, as then generally supposed, but must be in essence motion, for only motion had brought it into existence. As we follow Faraday’s recital of the successive changes in properties which follow upon additions of heat, in other words, of mechanical motion, the inference is irresistible that properties consist in the distinct motions of masses of definite form and size, these very motions, perhaps, deciding both the form and size of each mass.
CHAPTER XVI
MEASUREMENT
Methods beginning in rule-of-thumb proceed to the utmost refinement . . . The foot and cubit . . . The metric system . . . Refined measurement a means of discovery . . . The interferometer measures 1-5,000,000 inch . . . A light-wave as an unvarying unit of length.
A child notices that his bedroom is smaller than the family parlor, that to-day is warmer than yesterday was, that iron is much heavier than wood and less easily marked by a blow. The child becomes a well grown boy before he paces the length and breadth of rooms so as to compare their areas and add to his mensuration lesson an example from home. If instead of pacing he were to use a foot-rule, or a tape-line, so much the better. About this time he may begin to observe the thermometer, noting that within five hours, let us say, it has fallen eight degrees. As a child he took account of bigness or smallness, lightness or heaviness, warmth or cold; now he passes to measuring their amount. In so doing he spans in a few years what has required for mankind ages of history. When corn and peltries are bartered, or axes and calumets are bought and sold, a shrewd guess at sizes and weights is enough for the parties to the bargain. But when gold or gems change owners a balance of delicacy must be set up, and the moral code resounds with imprecations on all who tamper with its weights or beam. Perhaps the balance was suggested by the children’s teeter, that primitive means of sport which crosses one prone tree with another, playmates rising and falling at the ends of the upper, moving trunk. In essence the most refined balance of to-day is a teeter still. Its successive improvements register the transition from merely considering what a thing is, whether stone, wood, oil or what not, to ascertaining just how much there is of it; or, in formal phrase, to make and use an accurate balance means passing from the qualitative to the quantitative stage of inquiry. Before Lavoisier’s day it was thought that any part of a substance which disappeared in burning was annihilated. Lavoisier carefully gathered all the products of combustion, and with scales of precision showed that they weighed just as much as the elements before they were burned. He thus laid the corner-stone of modern chemistry by demonstrating that matter is invariable in its total quantity, notwithstanding all chemical unions or partings. Phases of energy other than gravity are now measured with instruments as much improved of late years as the balance; they tell us the great truth that energy like matter is constant in quantity, however much it may vary from form to form, however many the subtle and elusive disguises it may wear.