Dr. Carroll first allowed himself to be bitten by the mosquitoes, not the _anopheles_ but another variety known as the _stegomyia_. He fell ill with a bad attack of yellow fever, which very nearly cost him his life. Later, in the yellow fever hospital, Dr. Lazear deliberately allowed a mosquito to feed on his hand. In four days he was down with the disease in so acute a form that he died of it--a true martyr, if ever there was, to the cause of science and the welfare of mankind. These and other experiments proved conclusively that yellow fever, like malaria, is transmitted by mosquito bites, but it was still uncertain how soon after biting an infected person the mosquito becomes itself harmful and how soon a person stricken with malaria is able to infect a healthy mosquito. So further experiments were necessary, and volunteers were invited to offer themselves for this service. Everybody in the army knew what had happened to Doctors Carroll and Lazear, but in spite of this plenty of willing martyrs appeared. The first to present themselves were two young soldiers from Ohio, John R. Kissinger and John J. Moran. Dr. Reed talked the matter over with them, explaining fully the danger and suffering involved, and stating the money consideration offered by General Wood. Both young men declared that they were prepared to undergo the experiment, but only on condition that they should receive no pecuniary reward. When he heard this declaration, Dr. Reed touched his hat with profound respect, saying, "Gentlemen, I salute you!"[8] Kissinger took the disease from the mosquito bites, and recovered. A room was prepared for Moran, a sort of mosquito den into which fifteen gnats, all suffering from yellow fever, had been admitted. Major Reed describes what happened:-- At noon on the same day, five minutes after the mosquitoes had been placed therein, a plucky Ohio boy, Moran by name, clad only in his night-shirt and fresh from a bath, entered the room containing the mosquitoes, where he lay down for a period of thirty minutes. Within two minutes of Moran's entrance he was being bitten about the face and hands by the insects, that had promptly settled down upon him. Seven, in all, bit him at this visit. At 4.30 p.m. the same day, he again entered and remained twenty minutes, during which time five others bit him. The following day, at 4.30 p.m., he again entered and remained fifteen minutes, during which time three insects bit him; making the number fifteen that had fed at these three visits. On Christmas morning, at 11 a.m., this brave lad was stricken with yellow fever, and had a sharp attack, which he bore without a murmur.