Dr. Gorgas had also had the advantage of being a collaborator as well as a fellow officer of Dr. Reed in Cuba. Dr. Reed was one of the first army surgeons to become familiar with the theory that the yellow fever and the malarial fevers of the tropics were carried and distributed through the agency of mosquitoes. In fact, Dr. Reed himself became a victim to his desire for scientific knowledge, he having allowed himself to be bitten by a mosquito that had first filled itself with the virus of a yellow fever patient, and died as the result of the experiment. War on the Mosquito Dr. Gorgas carried on the work of the investigation and development of the mosquito theory after the death of Dr. Reed, and became a recognized world-wide authority on the science of tropical diseases and sanitation, when he was chosen as the officer to whom the sanitization of the Zone should be entrusted. He was given ample funds by the American Government and furnished with a force of men numbering more than 2000, his theory being that by the destruction of the breeding places of mosquitoes he could finally eliminate the mosquitoes themselves. In carrying out his plan the vegetation on either side of the canal for half a mile was cut down and burned, the dead trees destroyed, the low marshy places drained where possible; and where it was impossible to successfully drain the ground and water pools they were covered with a petroleum mixture. In fact, petroleum was found to be so effective that it came to be the favorite means of destroying the mosquitoes, and one approaching Colon today, if the wind is in the right quarter, may catch the odor of that ingredient one hundred miles at sea. It was found after investigation by Dr. Gorgas that the mosquito, called the stegomyia, was peculiarly partial to the yellow fever victim, and that after biting a yellow fever patient and becoming inoculated with the poison, the stegomyia became very active in its distribution to other subjects. A mosquito called the anopheles, by some peculiar freak of nature, had a like attraction for the victims of malarial diseases. And so, between the two kinds of mosquitoes there seemed to be a rivalry as to which could do the most damage. But fortunately neither one of these pestiferous insects could fly over a quarter of a mile, and so the theory of Dr. Gorgas was that by destroying their breeding places and eliminating them from the Canal Zone, he might preserve the health of the workers. Colon was overhauled by repaving the streets after first saturating the ground with petroleum, bringing in fresh water and constructing sewers. In fact, all the measures that were necessary to establish healthful conditions were used. The same course of treatment was given the City of Panama, much to the disgust of many of the Panamanian residents, who had been using water from wells and cisterns that had been dug two centuries before, when Panama was founded.