But the price per ton of his product was out of proportion to the expenses. While other men mined the ore he wrote a book on "Subterranean Vegetation." The details of business were not to his liking. His own private financial affairs were now turned over to Knuth, his modest fortune resolved into cash and invested in bonds that brought a low rate of interest. Freedom was his passion—to come and go at will was his desire. The thirst for travel was upon him—travel, not for adventure, but for knowledge.
He resigned his office and tramped with knapsack on back across the Alps. The habit of his mind was that of the naturalist-investigator. Geology, botany and zoology were his properties by divine right.
These sciences really form one—geognosy, or the science of the formation of the earth. The plants dissolve and disintegrate the rocks; the animal feeds upon the plants; and animal life makes new forms of vegetation possible. So the mineral, vegetable and animal kingdoms evolve together, constantly tending toward a greater degree of refinement and complexity.
The very highest form of animal life is man; and the highest type of man is evolved where there is a proper balance between the animal and the vegetable kingdoms.
Humboldt discovered very early in his career that the finest flowers grow where there are the finest birds, and man separated from birds, beasts and flowers could not possibly survive.
Just about this time, Humboldt, taking the cue from Goethe, said: "Man is a product of soil and climate, and is brother to the rocks, trees and animals. He is dependent on these, and all things seem to point to the truth that he has evolved from them. The accounts of special creation are interesting as archeology, but biology is distinctly the business of modern scientists. The scientist tells what he knows, and the theologist what he believes." And again we find Humboldt writing from Switzerland in Seventeen Hundred Ninety-six, making observations that have been recently unconsciously paraphrased by the United States Secretary of Agriculture, who said in a printed report: "Western farmers who raise and sell hogs and cattle, feeding them grain instead of selling it, are sure to acquire a competence. The farmers who sell grain are the ones who do not pay off their mortgages."
Says Humboldt:
"Here on the sides of these towering and forbidding mountains we find the most fertile and beautiful miniature farms, nestling in little valleys or on plateaus.
"Indeed, I heard today of a man falling out of his farm and being seriously injured. He ventured too near the edge.
"These Swiss gardens with their prosperous and intelligent owners are only possible through the fact that the owners keep all the cows and poultry that can comfortably exist on the acres. The peasants sell butter, cheese and eggs, instead of grain and vegetables exclusively.