CHAPTER XIX

  CERTAIN FIRST PRINCIPLES

  "What's the matter?" asked Kemp, when the Invisible Man admitted him.

  "Nothing," was the answer.

  "But, confound it! The smash?"

  "Fit of temper," said the Invisible Man. "Forgot this arm; and it'ssore."

  "You're rather liable to that sort of thing."

  "I am."

  Kemp walked across the room and picked up the fragments of brokenglass. "All the facts are out about you," said Kemp, standing upwith the glass in his hand; "all that happened in Iping, and downthe hill. The world has become aware of its invisible citizen. Butno one knows you are here."

  The Invisible Man swore.

  "The secret's out. I gather it was a secret. I don't know what yourplans are, but of course I'm anxious to help you."

  The Invisible Man sat down on the bed.

  "There's breakfast upstairs," said Kemp, speaking as easily aspossible, and he was delighted to find his strange guest rosewillingly. Kemp led the way up the narrow staircase to thebelvedere.

  "Before we can do anything else," said Kemp, "I must understand alittle more about this invisibility of yours." He had sat down,after one nervous glance out of the window, with the air of a manwho has talking to do. His doubts of the sanity of the entirebusiness flashed and vanished again as he looked across towhere Griffin sat at the breakfast-table--a headless, handlessdressing-gown, wiping unseen lips on a miraculously held serviette.

  "It's simple enough--and credible enough," said Griffin, puttingthe serviette aside and leaning the invisible head on an invisiblehand.

  "No doubt, to you, but--" Kemp laughed.

  "Well, yes; to me it seemed wonderful at first, no doubt. But now,great God! ... But we will do great things yet! I came on the stufffirst at Chesilstowe."

  "Chesilstowe?"

  "I went there after I left London. You know I dropped medicine andtook up physics? No; well, I did. _Light_ fascinated me."

  "Ah!"

  "Optical density! The whole subject is a network of riddles--anetwork with solutions glimmering elusively through. And being buttwo-and-twenty and full of enthusiasm, I said, 'I will devote mylife to this. This is worth while.' You know what fools we are attwo-and-twenty?"

  "Fools then or fools now," said Kemp.

  "As though knowing could be any satisfaction to a man!

  "But I went to work--like a slave. And I had hardly worked andthought about the matter six months before light came through oneof the meshes suddenly--blindingly! I found a general principleof pigments and refraction--a formula, a geometrical expressioninvolving four dimensions. Fools, common men, even commonmathematicians, do not know anything of what some general expressionmay mean to the student of molecular physics. In the books--thebooks that tramp has hidden--there are marvels, miracles! But thiswas not a method, it was an idea, that might lead to a method bywhich it would be possible, without changing any other property ofmatter--except, in some instances colours--to lower the refractiveindex of a substance, solid or liquid, to that of air--so far as allpractical purposes are concerned."

  "Phew!" said Kemp. "That's odd! But still I don't see quite ... Ican understand that thereby you could spoil a valuable stone, butpersonal invisibility is a far cry."

  "Precisely," said Griffin. "But consider, visibility depends on theaction of the visible bodies on light. Either a body absorbs light,or it reflects or refracts it, or does all these things. If itneither reflects nor refracts nor absorbs light, it cannot ofitself be visible. You see an opaque red box, for instance, becausethe colour absorbs some of the light and reflects the rest, all thered part of the light, to you. If it did not absorb any particularpart of the light, but reflected it all, then it would be a shiningwhite box. Silver! A diamond box would neither absorb much of thelight nor reflect much from the general surface, but just hereand there where the surfaces were favourable the light wouldbe reflected and refracted, so that you would get a brilliantappearance of flashing reflections and translucencies--a sort ofskeleton of light. A glass box would not be so brilliant, nor soclearly visible, as a diamond box, because there would be lessrefraction and reflection. See that? From certain points of viewyou would see quite clearly through it. Some kinds of glass wouldbe more visible than others, a box of flint glass would be brighterthan a box of ordinary window glass. A box of very thin commonglass would be hard to see in a bad light, because it would absorbhardly any light and refract and reflect very little. And if youput a sheet of common white glass in water, still more if youput it in some denser liquid than water, it would vanish almostaltogether, because light passing from water to glass is onlyslightly refracted or reflected or indeed affected in any way.It is almost as invisible as a jet of coal gas or hydrogen is inair. And for precisely the same reason!"

  "Yes," said Kemp, "that is pretty plain sailing."

  "And here is another fact you will know to be true. If a sheet ofglass is smashed, Kemp, and beaten into a powder, it becomes muchmore visible while it is in the air; it becomes at last an opaquewhite powder. This is because the powdering multiplies the surfacesof the glass at which refraction and reflection occur. In the sheetof glass there are only two surfaces; in the powder the light isreflected or refracted by each grain it passes through, and verylittle gets right through the powder. But if the white powderedglass is put into water, it forthwith vanishes. The powdered glassand water have much the same refractive index; that is, the lightundergoes very little refraction or reflection in passing from oneto the other.

  "You make the glass invisible by putting it into a liquid of nearlythe same refractive index; a transparent thing becomes invisible ifit is put in any medium of almost the same refractive index. And ifyou will consider only a second, you will see also that the powderof glass might be made to vanish in air, if its refractive indexcould be made the same as that of air; for then there would be norefraction or reflection as the light passed from glass to air."

  "Yes, yes," said Kemp. "But a man's not powdered glass!"

  "No," said Griffin. "He's more transparent!"

  "Nonsense!"

  "That from a doctor! How one forgets! Have you already forgottenyour physics, in ten years? Just think of all the things that aretransparent and seem not to be so. Paper, for instance, is made upof transparent fibres, and it is white and opaque only for the samereason that a powder of glass is white and opaque. Oil white paper,fill up the interstices between the particles with oil so that thereis no longer refraction or reflection except at the surfaces, andit becomes as transparent as glass. And not only paper, but cottonfibre, linen fibre, wool fibre, woody fibre, and _bone_, Kemp,_flesh_, Kemp, _hair_, Kemp, _nails_ and _nerves_, Kemp, in factthe whole fabric of a man except the red of his blood and the blackpigment of hair, are all made up of transparent, colourless tissue.So little suffices to make us visible one to the other. For themost part the fibres of a living creature are no more opaque thanwater."

  "Great Heavens!" cried Kemp. "Of course, of course! I was thinkingonly last night of the sea larvae and all jelly-fish!"

  "_Now_ you have me! And all that I knew and had in mind a year afterI left London--six years ago. But I kept it to myself. I had to domy work under frightful disadvantages. Oliver, my professor, was ascientific bounder, a journalist by instinct, a thief of ideas--hewas always prying! And you know the knavish system of the scientificworld. I simply would not publish, and let him share my credit. Iwent on working; I got nearer and nearer making my formula into anexperiment, a reality. I told no living soul, because I meant toflash my work upon the world with crushing effect and become famousat a blow. I took up the question of pigments to fill up certaingaps. And suddenly, not by design but by accident, I made adiscovery in physiology."

  "Yes?"

  "You know the red colouring matter of blood; it can be madewhite--colourless--and remain with all the functions it has now!"

  Kemp gave a cry of incredulous amazement.

  The Invisible Man rose
and began pacing the little study. "You maywell exclaim. I remember that night. It was late at night--in thedaytime one was bothered with the gaping, silly students--and Iworked then sometimes till dawn. It came suddenly, splendid andcomplete in my mind. I was alone; the laboratory was still, with thetall lights burning brightly and silently. In all my great momentsI have been alone. 'One could make an animal--a tissue--transparent!One could make it invisible! All except the pigments--I could beinvisible!' I said, suddenly realising what it meant to be an albinowith such knowledge. It was overwhelming. I left the filtering I wasdoing, and went and stared out of the great window at the stars.'I could be invisible!' I repeated.

  "To do such a thing would be to transcend magic. And I beheld,unclouded by doubt, a magnificent vision of all that invisibilitymight mean to a man--the mystery, the power, the freedom. DrawbacksI saw none. You have only to think! And I, a shabby, poverty-struck,hemmed-in demonstrator, teaching fools in a provincial college,might suddenly become--this. I ask you, Kemp if _you_ ... Anyone, Itell you, would have flung himself upon that research. And I workedthree years, and every mountain of difficulty I toiled over showedanother from its summit. The infinite details! And the exasperation!A professor, a provincial professor, always prying. 'When are yougoing to publish this work of yours?' was his everlasting question.And the students, the cramped means! Three years I had of it--

  "And after three years of secrecy and exasperation, I found that tocomplete it was impossible--impossible."

  "How?" asked Kemp.

  "Money," said the Invisible Man, and went again to stare out of thewindow.

  He turned around abruptly. "I robbed the old man--robbed myfather.

  "The money was not his, and he shot himself."