A simple argument, which sped like an arrow to the final discovery. Nothing seemed more _incredible_ than the fact that in the malarial regions good air and fertile soil were to be found, that it was possible to breathe that air morning and evening and remain in perfect health, so long as one was not bitten by mosquitoes, and that the innumerable peasants who were wasted by malarial anemia would be saved and restored if they protected themselves by mosquito-netting. But after the first stupefaction, when men were convinced of the facts, there was an outcry from all the intelligent: How was it possible that we did not find it out before? Was not the cycle of the protozoa a well-known fact? Did not every one declare that the system of circulation was closed and impervious to micro-organisms? Was it not natural to think that only a blood-sucking insect could innoculate it? How many students _felt_ that glory had passed close to them, and were amazed and saddened by the knowledge, like the disciples of Emmaeus, who said to each other when the Master disappeared before they recognized Him: "Did not our hearts burn within us when He spoke and expounded the Scriptures to us?" Many must have thought: We worked so laboriously only to encumber our minds, and yet but one thing was needful: we should have been humble and simple, but independent. Instead, we filled our souls with darkness, and the ray that would have made us see, could not penetrate to us. Let us take some grosser errors. As far back as the days of the Greek civilization it was known empirically that "stones can fall from the sky." Falls of aerolites are recorded in the most ancient Chinese chronicles. In the Middle Ages and in modern times intimations of the fall of aerolites have increased in frequency. Remarkable facts are indeed recorded in history in connection with similar phenomena: the meteorite which fell in 1492 served the Emperor Maximilian I of Germany as a pretext to excite Christendom to a war against the Turks. Nevertheless, the phenomenon was not admitted by men of science until the eighteenth century. One of the largest meteorites on record was that which fell near Agram in 1751; it weighed about forty kilogrammes, and was deposited and catalogued in the court mineralogical museum at Vienna. This is what Stuetz, a German savant, had to say on the subject in 1790: "Those ignorant of natural history may believe that iron has fallen from the sky, and even educated men in Germany may have believed this in 1751, taking into account the universal ignorance then prevalent as to natural history and physics; but in our times it would be unpardonable to admit even the plausibility of such fables."