(6) R. La Roche:  Yellow Fever, 2 vols., Philadelphia, 1855.

Many scientific discoveries have afforded brilliant illustrations of method in research, but in the work of these men one is at a loss to know which to admire more—­the remarkable accuracy and precision of the experiments, or the heroism of the men—­officers and rank and file of the United States Army; they knew all the time that they were playing with death, and some of them had to pay the penalty!  The demonstration was successful—­beyond peradventure—­that yellow fever could be transmitted by mosquitoes, and equally the negative proposition—­that it could not be transmitted by fomites.  An interval of twelve or more days was found to be necessary after the mosquito has bitten a yellow fever patient before it is capable of transmitting the infection.  Lazear permitted himself to be bitten by a stray mosquito while conducting his experiments in the yellow fever hospital.  Bitten on the thirteenth, he sickened on the eighteenth and died on the twenty-fifth of September, but not until he had succeeded in showing in two instances that mosquitoes could convey the infection.  He added another to the long list of members of the profession who have laid down their lives in search of the causes of disease.  Of such men as Lazear and of Myers of the Liverpool Yellow-Fever Commission, Dutton and young Manson, may fitly be sung from the noblest of American poems the tribute which Lowell paid to Harvard’s sons who fell in the War of Secession: 

     Many in sad faith sought for her,
     Many with crossed hands sighed for her;
     But these, our brothers, fought for her,
     At life’s dear peril wrought for her,
     So loved her that they died for her.

Fortunately, the commander-in-chief at the time in Cuba was General Leonard Wood, who had been an army surgeon, and he was the first to appreciate the importance of the discovery.  The sanitation of Havana was placed in the hands of Dr. Gorgas, and within nine months the city was cleared of yellow fever, and, with the exception of a slight outbreak after the withdrawal of the American troops, has since remained free from a disease which had been its scourge for centuries.  As General Wood remarked, “Reed’s discovery has resulted in the saving of more lives annually than were lost in the Cuban War, and saves the commercial interest of the world a greater financial loss each year than the cost of the Cuban War.  He came to Cuba at a time when one third of the officers of my staff died of yellow fever, and we were discouraged at the failure of our efforts to control it.”  Following the example of Havana other centres were attacked, at Vera Cruz and in Brazil, with the same success, and it is safe to say that now, thanks to the researches of Reed and his colleagues, with proper measures, no country need fear a paralyzing outbreak of this once dreaded disease.