In spite of the opposition of the American and British delegates the First Hague Conference adopted the clause, "The contracting powers agree to abstain from the use of projectiles the [sole] object of which is the diffusion of asphyxiating or deleterious gases." The word "sole" (_unique_) which appears in the original French text of The Hague convention is left out of the official English translation. This is a strange omission considering that the French and British defended their use of explosives which diffuse asphyxiating and deleterious gases on the ground that this was not the "sole" purpose of the bombs but merely an accidental effect of the nitric powder used. The Hague Congress of 1907 placed in its rules for war: "It is expressly forbidden to employ poisons or poisonous weapons." But such attempts to rule out new and more effective means of warfare are likely to prove futile in any serious conflict and the restriction gives the advantage to the most unscrupulous side. We Americans, if ever we give our assent to such an agreement, would of course keep it, but our enemy--whoever he may be in the future--will be, as he always has been, utterly without principle and will not hesitate to employ any weapon against us. Besides, as the Germans held, chemical warfare favors the army that is most intelligent, resourceful and disciplined and the nation that stands highest in science and industry. This advantage, let us hope, will be on our side. CHAPTER XIII PRODUCTS OF THE ELECTRIC FURNACE The control of man over the materials of nature has been vastly enhanced by the recent extension of the range of temperature at his command. When Fahrenheit stuck the bulb of his thermometer into a mixture of snow and salt he thought he had reached the nadir of temperature, so he scratched a mark on the tube where the mercury stood and called it zero. But we know that absolute zero, the total absence of heat, is 459 of Fahrenheit's degrees lower than his zero point. The modern scientist can get close to that lowest limit by making use of the cooling by the expansion principle. He first liquefies air under pressure and then releasing the pressure allows it to boil off. A tube of hydrogen immersed in the liquid air as it evaporates is cooled down until it can be liquefied. Then the boiling hydrogen is used to liquefy helium, and as this boils off it lowers the temperature to within three or four degrees of absolute zero.