Dr. Carlos Finlay, of Havana, the physician just mentioned as being a member of our Commission, had ever since the year 1881 been investigating, thinking of and writing about the relation of the mosquito to yellow fever. He had convinced himself that this insect was the means whereby the disease was conveyed from person to person. Others before Dr. Finlay’s time had referred to the possibility of this being the case, notably Dr. J. C. Nott, of Mobile, Alabama. In March, 1848, he published in the New Orleans Medical Journal an article in which he maintained that the spread of yellow fever could not be explained by the assumption of a diffusible miasm in the atmosphere. But Dr. Finlay had given more attention to this subject than anyone who had gone before him. He had written upon it constantly from the year 1881. His argument from the then known facts with regard to yellow fever, showing from these facts that it was probably the mosquito that conveyed this disease, was most beautiful and logical. But a still more beautiful piece of reasoning was the induction that it was the stegomyia mosquito, out of the six or seven hundred species of mosquitoes, that conveyed yellow fever.
Dr. Finlay, in the twenty years before we went to Havana, had done a great deal of experimenting on the human subject with regard to yellow fever. But he had not been successful in transmitting the disease. He had no means of knowing that it took the mosquito twelve days from the time when she swallowed the blood of a yellow-fever patient to become herself infectious. Not knowing this fact, it was perfectly natural for Dr. Finlay to use his mosquitoes upon his experimental cases within the first four or five days after they had bitten a yellow-fever patient. At any rate, in a large number of experimental bitings of the human subject he did not have a single case in which the evidence was conclusive that yellow fever had been conveyed by the mosquito. Reed says of Finlay: “To Dr. Carlos Finlay, of Havana, must be given, however, full credit for the theory of the propagation of yellow fever by means of the mosquito, which he proposed in a paper read before the Royal Academy in that city at its session on the 14th day of August, 1881.”
The Reed Board, after many months of inconclusive work in other directions, turned their attention to Dr. Finlay’s mosquito theory. Dr. Reed discussed the matter with Dr. Finlay a good deal before he commenced his mosquito work, and was thoroughly familiar with Dr. Finlay’s arguments and ideas on the subject. Indeed, we all knew Dr. Finlay well, but were rather inclined to make light of his ideas, and none more so than I. He and I met every day on the yellow-fever Commission above referred to, and it is probable that every day for more than a year we had more or less discussion on this subject.
Dr. Finlay is a most lovable man in character and personality, and no one could be constantly thrown with him as I was daily for several years without becoming warmly attached to him and forming the highest estimate of his scientific honesty and straightforwardness. Being very familiar with yellow fever, both historically and clinically, I was constantly bringing to his notice instances in the past which could not be accounted for on the mosquito theory. He, with the greatest ingenuity, was equally ready to explain how the mosquito theory could be turned so as to meet just this condition.
Dr. Finlay is still living in retirement and comfortable old age in the city of Havana. When the American forces were withdrawn from Cuba in 1902, Dr. Finlay succeeded me as health officer under the Cuban Government. He has since been retired on a pension by that Government. I called on him in Havana several years ago, and found him enjoying his more than eighty years of age, and the honors that were being heaped upon him. He is one of the few great men who has had his work recognized during his lifetime.
Dr. Reed got from Dr. Finlay the eggs from which he raised the mosquitoes used in his experimental work. Dr. Finlay says on page 1 of his “Agreement between the History of Yellow Fever and Its Transmission by the Culex Mosquito”: “The experiments made by Drs. Reed, Carroll, Agramonte and Lazear were started in June, 1900, with a brood hatched from eggs of the identical insect which at Dr. Lazear’s request I had handed to him. All the successful experiments have hitherto been made with that particular mosquito.”
Dr. Reed says in his paper, “The Etiology of Yellow Fever, Preliminary Note”: “We here desire to express our sincere thanks to Dr. Finlay who accorded us a most courteous interview and has gladly placed at our disposal his several publications relating to yellow fever, during the past nineteen years; and also for ova of the species of mosquito with which he had made his several inoculations. An important observation to be here recorded is that according to Finlay’s statement, thirty days prior to our visit, these ova had been deposited by a female just at the edge of the water in a small basin, whose contents had been allowed to slightly evaporate; so that these ova were at the time of our visit, entirely above contact with the water. Notwithstanding this long interval after deposition, they were promptly converted into the larval stage, after a short period, by raising the level of the water in the basin. With the mosquitoes thus obtained we had been able to conduct our experiments. Specimens of this mosquito forwarded to Mr. L. O. Howard, Entomologist, Department of Agriculture, Washington, D. C., were kindly identified as culex fasciatus—Fabr.”
CHAPTER II
THE EXPERIMENTS OF THE REED BOARD
After consultation, the Reed Board determined to experiment to see whether the mosquito really did convey yellow fever. But it was necessary to have a good deal of money and sufficient authority before starting in. The Board had come to Cuba for entirely different investigations, and had not been supplied with sufficient funds for these experiments. Fortunately for the cause of science and of humanity, we had as Governor-General of Cuba at that time General Leonard Wood, of the United States Army. General Wood had been educated as a physician, and had a very proper idea of the great advantages which would accrue to the world if we could establish the fact that yellow fever was conveyed by the mosquito, and his medical training made him a very competent judge as to the steps necessary to establish such fact.
General Wood during the whole course of the investigations took the greatest interest in the experiments, and assisted the Board in every way he could. Dr. Reed outlined to General Wood the course he expected to pursue, and General Wood was so convinced by Dr. Reed’s argument that he authorized the expenditure from Cuban funds of a sufficient sum and gave Dr. Reed ample powers as to the method of expenditure.