"You have discovered something?" Dixie asked.
"I think so," answered Grant. "But first let us hear what you have discovered, to see if it fits in with my find."
"It isn't an awful lot," answered Dixie. "In the first place every fire has started in the portion of the field nearest to the road or a railroad, and almost invariably there has been water near the place where the fire started. The only strangers which have been observed in the vicinity were a couple of traveling geologists, who did most of their traveling on foot and carried the samples they had collected in little cloth bags. That is about all."
"It is enough," said Grant. "The point of origin of the fire in the first field I examined attracted my attention because it had been burned with a more intense heat than burning grain would make. I took a sample there and then for purposes of comparison took another sample of the soil some distance away. It was easy to determine the place of the origin of the fires in the other fields, for in each place I found a spot where there had been intense heat. The samples from these spots which I have analyzed show a large percentage of phosphorus oxide, while the other samples are free from it. Phosphorus oxide is formed by the burning of phosphorus."
"Which makes it very clear as to how the fires started," commented Dixie.
"It may be to you," interjected the farmer, "but I can't see what started the phosphorus burning even if some was placed in the field."
"Phosphorus has a peculiar property," explained Grant. "When it is in a certain degree of solution it unites readily with the oxygen in the air, which is merely another way of saying that it burns. The burning of the wheat fields is an example of the methods of the I.W.W. prompted by Imperial Germany's desire to keep supplies of food from reaching the Allies. These bogus geologists had small bags filled with dry phosphorus. To accomplish their design it was merely necessary to give the bag a soaking with water and throw it into a field. Several hours afterward when the sun had dried the phosphorus to the degree of solution where it unites with the air it would burst into flame and ignite the wheat."
As a convincing demonstration to the farmer Grant procured a small piece of phosphorus and showed him how it would start burning by merely dropping it into water.
"You see it floats when placed on water," said Grant as the farmer watched the little blue flame with changing expressions. "The underpart is too thoroughly saturated while the top part is dry. Between there is a section which is at the proper percentage of solution and hence the burning."
"Let me assure you," said the farmer finally with a set jaw, "that the wheat lands are going to be a mighty unhealthy place from now on, for I.W.W.'s, German spies or anyone else carrying little sacks of anything."