62 



which I had previously proved to carry malaria in India, and found in 

 similar insects in Italy the stages of the development of the parasites 

 previously described by me. I regret that I must add that, for the rest, 

 the writings of these three persons, especially of the last, constitute 

 one of the most impudent scientific piracies on record, and are little 

 to be trusted except when directly based on the works of more reliable 

 observers.* 



Regarding yellow fever, FINLAY, of Havana, has long held the 

 hypothesis that the disease is conveyed by mosquitoes. The fact has 

 been recently quite conclusively proved by LAZEAR, CARROLL, REED, 

 and AGRAMONTE, by direct inoculation of the disease in a number of 

 persons, by means of mosquitoes fed twelve or more days previously 

 on patients with the disease. LAZEAR, who was bitten in this manner, 

 died. Attempts to infect numerous persons by means of the clothing 

 of patients, and by other methods, all failed. t 



As soon as the exact method of infection in malarial fever was 

 determined, it became at once necessary to attack the question of 

 prevention in the light of the new discovery. I recommended, over 

 and over again, J the principle of the extermination of mosquitoes in 

 towns, advocated above, but without succeeding in persuading my 

 countrymen to adopt it; though, in 1899, I went with Dr. ARNETT 

 and Mr. AUSTEN to Sierra Leone to make a thorough local investi- 

 gation of the subject. Meantime KOCH, with great energy, attacked 

 the same question in certain German tropical possessions ; but he 

 recommended another method that of cinchonising whole com- 

 munities. Simultaneously the Italians employed KOCH'S method, 

 together with window screens ; and MANSON clearly demonstrated 

 the value of the latter by his Campagna experiment of 1900. In our 

 Sierra Leone report we had mentioned the advisability of segrega- 

 tion for Europeans in the tropics ; and CHRISTOPHERS, STEPHENS, 

 ARNETT, BUTTON, and ELLIOTT strongly advocated this idea. 



* The facts as regards priority have been impartially marshalled by NUTTALL, 

 in the Quarterly Journal of Microscopical Science, May, 1901. See also my letters 

 in the Policlinico, Rome, Nov. 1900, and May, 1901. 



f New York Medical Record, i6th February, 1901. 



% Letter to Government of India, partly published in Indian Medical Gazette, 

 July, 1899. Also British Medical Journal, ist July, 1899 ; Lancet, 1900, vol. n, 

 page 1400 ; Journal of Society of Arts, soth November, 1900. 



Memoir II. of the Liverpool Tropical School publications, 1899. 



