It's a form of nitrogen, you see, directly obtained from air." "At what cost ?" "One ton of fixed nitrogen in that form costs about $150 or $160." "Indeed ?" commented Flint.

"The same amount, combined in Chile saltpeter, comes to-- ?" "A little over $300, sir." "Hear that, Wally ?" exclaimed the Billionaire, turning to his now interested associate.

"Even if this idea never goes a step farther, there's a gold mine in just the production of fertilizer from air! But, after all, that will only be a by-product.

It's the oxygen we're after, and must have!" He faced Herzog again.
"Is any oxygen liberated, during the process ?" he demanded.
"At one stage, yes, sir.

But in the present process, it is absorbed, also." Flint's eyebrows contracted nervously.