SCIENCE. 



167 



come by counter force. But if a portion of the gravity 

 of the body has become transformed into this motion 

 there will certainly be less to tr nsform during the next 

 second. Yet in the next second the body adds to its 32 

 feet per second 16 feet more derived from gravity, and 

 thus falls 48 feet, ending with a velocity of 64 ieet per 

 second. In the third second it adds 16 feet to this 64, 

 and falls 80 feet. And so on continuously, so far as ob- 

 servation has gone. 



This certainly does not look like a transformation of 

 gravity into motion, since the gravity appears to continue 

 undiminished. And as to potential force, or possibility 

 of motion, being converted into motion, I shall not at- 

 tempt to combat it, for it is a sorry task to wrestle with 

 an antagonist who changes into a mist when you attempt 

 to grasp him. Gravity is something definite, whatever 

 that something is, but this will-of-the-wisp of potentiality 

 certainly lacks the bones of a solid body. 



But if not gravity or potentiality what is it that be- 

 comes motion in the ball that falls towards the earth, 

 and in the earth that falls towards the ball ? This may 

 seem a difficult question, and yet it admits of but one 

 answer. Nothing becomes motion. Nothing can be- 

 come motion. Motion is motion and cannot possibly be 

 or become anything else. The motion which appears in 

 the falling body was not created for the purpose. It 

 existed in the falling body in some other form, and has 

 been simply transformed, not created. Every mass of 

 matter has its internal motions ; its electrical, magnetic 

 and chemical energies, which are more or less engaged 

 in preserving the integrity of its molecules or of its mass ; 

 and its heat energy, which is engaged in a constant effort 

 to overcome the integrity of its mass. The particles of 

 the mass dart backward and forward continually. They 

 would dart in one direction only were they not restrained 

 by each other's resisting energies, and by external re- 

 sistance. Consequently, any external energy which aids 

 their vigor of movement in one direction and resists it in 

 the opposite must give them a combined excess of vigor 

 in that direction. They must all move more vigorously 

 in that direction than in the opposite ; that is, the mass 

 must move as a whole in that direction. And this move- 

 ment once gained is positive until overcome by exterior 

 resistance. It is a definite energy which cannot be lost 

 unless it be given to some other substance. 



Such is the true principle at work in falling motion. 

 Terrestrial gravity is the external energy which aids the 

 vigor of t^e heat motion of particles in one direction and 

 resists it in the other. This force is increasing. Al- 

 though a mass be not fal'ing to the earth its particles are 

 incessantly falling. The supporting body resists their 

 fall and their excess energy in this direction expends it- 

 self upon this body. But if the support be removed there is 

 no longer any resistance to their fall. The particles strike 

 further downward than they return, since gravity aids 

 their down stroke and retards their upstroke. Thus at each 

 vibrarion ot the particles the mass slightly descends. 

 These slight descents continue. They are the energy 

 derived from the pull of gravitative attraction. But each 

 slight descent produces a fixed vigor of downward mo- 

 tion of the mass as a whole, and this vigor of motion is 

 increased by constant new increments, so that the 

 falling speed of the body rapidly increases. 



This is the true meaning of potential energy— a change 

 in the direction of motions already exisfng. No motion 

 is created, or borrowed from any other condition of 

 nature. The body gains force in one direction under the 

 pull of gravity, but it is the force of a motive vigor which 

 it already possessed, and which, instead of exerting itself 

 equally in all directions, now exerts part of its energy 

 specially in one direction. And this change in the direc- 

 tion of its energies is balanced by an equal opposite change 

 in the direction of the earth's energies. The body does 

 not possess the possibility of always falling, but it pos- 

 sesses the reality of always falling. Its particles con- 



stantly fall. But when it is supported their falls cannot 

 accumulate. Each single fall is too slight to be observed, 

 and the effect of each fall is overcome by resistance be- 

 fore another can be added to it. But these persistant 

 falls produce a constant pressure upon the resisting sub- 

 stance, and constitute the weight of the body. It is 

 on removal of the support that these rapidly repeated 

 effects can be continuously added to each othei, and be- 

 come a visible descent. But the distance of the fall of 

 the particles during each vibration is the same whether 

 the body be supported or rapidly descending. It is 

 only the preservation and accumulation of the positive 

 mass motion given to the body by each slight fall, which 

 causes the rapid increase in falling speed. These accu- 

 mulating motions form an energy of motion separate from 

 that of the fall, and which would keep the mass in motion 

 at a fixed rate of speed were the force of gravity to sud- 

 denly vanish. 



I would like to say a word here in reference to the pre- 

 sumed heated condition of the nebular mass from which 

 it is claimed that the solar system originated. There is 

 another reason than that advanced by Mr. Larkin, which 

 renders it very improbable that the nebula was greatly 

 heated. It is one thing to contain heat, another thing to 

 be in what we call a heated state, that is, in a state of high 

 temperature. For temperature and absolute heat are very 

 different things. A mass of water at 32° contains far 

 more heat than a mass of ice at the same temperature. 

 And so a mass of wa'er gas at 212 contains far more 

 heat than an equal mass of water at that temperature. 

 This rule probably holds good in all cases ; namely, that 

 as density diminishes the heat capacity increases, so that 

 a very rare gas may contain a vastly greater quantity of 

 heat than a solid at the same temperature. We see this 

 exemplified in the matter of space. Heat has been pour- 

 ing into it from the contracting spheres for an enormous 

 period, yet its capacity for heat is so excessive that this 

 outflowing heat has probably had very little effect in rais- 

 ing its temperature. 



Such a consideration applies directly to the original 

 nebula of the solar system. It was a very rare gas, and 

 therefore had great capacity for heat. Its latent heat 

 may have been great, and its effective temperature low. 

 It was only after it began to rapidly lose heat that its 

 temperature rose. For the contraction of the nebular 

 mass must have, by condensing its substance, lessened 

 its capacity for heat. If this change in condition took 

 place more rapidly than radiation could balance it there 

 must have been a steady increase in temperature, instead 

 of a decrease as usually assumed. For all that we know 

 to the contrary this phase of the process may not yet be 

 completed. Contraction of the solar mass may yet be 

 increasing its sensible heat, by lowering its capacity for 

 heat, or its power of containing latent heat, more rapidly 

 than this is balanced by radiation. In such a not impos- 

 sible condition of affairs the sun would be yet rising in- 

 stead of lowering in temperature, losing heat while in- 

 creasing its apparent or sensible heat, and its process of 

 actual cooling be not yet begun. 



2223 Spring Garden St. Philadelphia. CHARLES MORRIS. 



A Cause of Deterioratton in Cloth. — Goods dyed 

 rust, buff, or chamois shades with salts of iron occasionally 

 undergo a slow combustion. The ferric oxide is alternately 

 reduced by the organic matter of the tissue and re-oxidized 

 by the oxygen of the air. 



At a Berlin feather-dyeing establishment an ostrich 

 feather dyed in shades with methyl-violet was Iayed upon 

 a paper upon which some ammonia had been poured but 

 had dried up again. After a time the feather became par- 

 tially green, the green passing gradually into violet, and 

 producing an extraordinary effect. This reaction is being 

 utilized in feather-dyeing, and will probably be applied in 

 the manufacture of artificial flowers. — M. Balland. 



