The white cipher

by Henry Leverage

“Werke-Maintz,� said Fay.

“Go on—it reads easy after your eyes accustom themselves to the dark. What’s between the next lines of typing?â€�

“Der est.... Blau die.... Alizarine.... Sapphire.... H₂SO₄ ... HNO₃—â€�

“And the next?�

“Carbanthrene Blau...?�

“Yes, and indigo and all the fast colors are there. They are worked out to the minutest details and formulae. They throw the field wide open to the world. There will be no more secret dyes!�

Sir Richard grasped Fay’s right arm and continued:

“D’you see the trick, now? The trifle—lighter than any air? D’you see what baffled the cipher experts of four countries for two years?â€�

“Yes, I see it, now,� said Fay. “The formulae are written in radium.�

“Radium salt, which is white, upon white paper!â€� blurted Sir Richard. “The only way you could ever see it—is in the dark!â€�