"Sulpho-" Quotes from Famous Books
 ... iron chloride, diluted until the writing is invisible when dry," he hurried on. "I will just make a few scratches on this fourth sheet of paper - so. It leaves no mark. But it has the remarkable property of becoming red in vapour of sulpho-cyanide. Here is a long-necked flask of the gas, made by sulphuric acid acting on potassium sulphocyanide. Keep back, Dr. Waterworth, for it would be very dangerous for you to get even a whiff of this in your condition. Ah! See ...
— The Poisoned Pen • Arthur B. Reeve |
