“I class them as Ganot does,” quietly returned the professor. “There is spontaneous phosphorescence, such as in certain vegetables and animals. Phosphorescence by elevation of temperature, as best observed in species of diamonds, and particularly in chlorophane, a variety of fluorspar, which, when heated to three or four hundred degrees, suddenly becomes luminous, emitting a greenish-blue light.”
“Thank you, thank you,” cried Mr. Butterworth, while the other guests politely counterfeited an interest. “You have refreshed my recollection greatly. The next in order is phosphorescence by mechanical effects, such as by friction, percussion and cleavage, as seen when two quartz crystals are rubbed together in the darkness, or when a lump of sugar is broken. My faith, it seems only yesterday I was deep in my books! Let’s see, phosphorescence by electricity is the fourth cause, such as results from the friction of mercury against the glass in a barometric tube. By George, Surrogate, I’ll wager you can’t recall so much of your chemistry, eh?”
“No, no; hardly,” laughed the Surrogate. “But come, you’re a boaster. You haven’t finished yet. The professor said five causes. Name the fifth, huh.”
Mr. Butterworth fumbled his chin in perplexity, to the great enjoyment of his guests, and finally surrendered,
“I know it, but I can’t recall it. The Professor will have to come to the rescue again.”
Professor Quell stroked his short, stubby beard with thoughtful deliberation and was silent for some moments before he said,
“The fifth cause is phosphorescence by insolation, or exposure to the sun.”
“An example, please,” challenged the Surrogate playfully.
In a class-room voice the Professor continued,
“A large number of organic substances, after being exposed to the action of the solar light, or of the diffused light of the atmosphere, emit in darkness a phosphorescence, such as dry paper, silk, cane-sugar, milk-sugar, amber, and the teeth.”
“Bravo!” applauded Mr. Butterworth. “Do you know I love chemistry and have always regretted I did not turn to it instead of the law. There’s nothing prosaic in chemistry, no ruts, no routine, no beaten path of precedent. Every chemist is an explorer. But, Professor, I observe you’ve left out one of the most universal phosphorescent effects under the fifth cause.”
“I did not assume to be exhaustive,” hastily obtruded the Professor.
“But what one does our host refer to?” rallied Mr. Riggsley.
“I referred to snow!” slowly replied Mr. Butterworth, in a loud voice.
Professor Quell bent a mathematical stare upon the speaker and settled back in his chair. The intensity of his gaze would have been commented upon had not the white-haired butler at this juncture thrown the party into confusion by crying out,
“Oh, come to the windows at once, gentlemen, I beg of you! Look! look!”
With a muttered exclamation Mr. Butterworth pushed back his chair and the others quickly followed his example and rushed to the windows.
“What is it? Make room for the court! I’ll hand down an opinion. Bless my soul!” exploded the Surrogate, backing from the window and blinking rapidly and then flattening his nose against the pane.
A volley of ejaculations and excited queries radiated from the clustered heads as the guests stared forth incredulously into the night. Then the butler turned off the lights so that the men might see the better. What astonished and filled the gazers with wonder was the figure of a gigantic ostrich just beneath the windows and apparently in pursuit of a huge human skeleton. Farther away, sharply outlined in black against the soft gray whiteness of the snow, was the startling interrogation, “Are we all insane?” And what caused new conjecture was the boldly printed direction, “Read Quell on ‘Winter Phenomena.’ ”
“What kind of a joke is this?” exclaimed Mr. Riggsley, his heart sinking as he feared the dinner had been planned for a wide-reaching purpose.
“Bless me! An ostrich!” babbled the Surrogate, rubbing his eyes.
“Great Scott!” bawled a young assistant corporation counsel from the end window. “Come down here. Here’s an elephant!”
“There’s an alligator chasing a rabbit!” shouted a third.
“Can it be possible!” stuttered the Surrogate. “Upon my soul, I believe this is a trick!”
“You’re more suspicious than poor Dr. Pinkey was,” laughed Mr. Butterworth, switching on the lights. “He believed he was the victim. Why, where’s Professor Quell?”
A hasty scrutiny of the room failed to discover that learned gentleman.
“Now that’s too bad — he’s taken fright and run away. As I got my hint from his book on ‘Winter Phenomena’ it’s no more than right he should be here to take the credit.”
“What does this mean, Mr. Butterworth?” hoarsely demanded Mr. Riggsley, who was utterly dumfounded by the disappearance of his client.
“Professor Quell’s work informs us how the action of sunlight on the snow creates a phosphorescence,” blandly replied Mr. Butterworth. “Snow is one of the substances that becomes phosphorescent in darkness after insolation, or exposure to the solar light. Professor Quell suggests that one take a blanket and spread it on the snow during a sunshiny day and then remove it at sundown. The square of snow thus shut off from the solar light will retain its shape accurately at night, having no phosphorescence, and will show up in sharp contrast with the surrounding phosphorescent areas. Should you approach the dark square it will not disappear. It would be the same as if you were gazing at a black shadow. You could make accurate measurements of it. But, of course, should you approach with a lighted lantern it would vanish and you’d find nothing but white snow.”
“This foolery leads to what, sir?” harshly demanded Mr. Riggsley, pale with passion as he began to believe he had been thoroughly duped.
“It gives a rational explanation of Dr. Pinkey’s irrational testimony,” quietly answered Mr. Butterworth. “It explains how he saw things in the snow, yet found the surface unmarred when he investigated. In short, someone, desirous of impeaching his testimony in some instance like the Asher will-contest, took advantage of the servants’ absence from the mansion, plus Mr. Asher’s absence, and placed figures, probably made of cardboard or paper, on the snow beneath the smoking-room windows. The figures were removed before anyone returned home. Then, sir, as evening advanced and the great snow areas responded with the ghostly light stored up in their cold bosoms during the day, the patches covered by the cardboard or paper had no phosphorescence to throw off, and as result the doctor saw things and even reached the point of condemning his own intellect.”
“Is it possible!” ejaculated the Surrogate.
“Not only possible, but deplorable that Professor Quell should use his great talent in a miserable attempt to defraud a girl!” emphatically denounced the old lawyer. “What’s more, I have located the telephone-operator and stableman. By them I can prove Quell telephoned from the junction in person, suggesting the tandem hitch and the jaunting-car; that he brought the drum to Mr. Asher, and that it was Quell who wrote the letter informing the old man his niece was at death’s door in the hospital. He used a dilute solution of chloride of cobalt, which was invisible when dry and in a normal temperature. He bribed the stableman, who carried the mail, to heat the letter in the oven so that it would be perfectly legible when presented to Mr. Asher. By the time the housekeeper reached the room it had faded out again.”
“This is monstrous—” weakly began Mr. Riggsley.
“It is monstrous, and I am pleased to state that Mr. Riggsley believed his cause an honest one,” announced Mr. Butterworth. “But let us take the lanterns and make the test Dr. Pinkey did. He must be thoroughly exonerated from his self-accusation and be put right with the public.”