Make fair allowance for the wide variation, from year to year, of the number of yellow fever cases in any town within the geographical belt of the disease; admit that a town may, in the course of nature, have many hundred cases in one year, and only half a dozen in another year. Again, make fair allowance for all other good influences of the American occupation of Cuba, beside those that were concerned with the stamping out of _Culex_; admit that the general death-rate of Havana, in the last February of Spanish rule (1898), was 82.32 per thousand, and in February 1901, was 19.32. Still, there is an example here, in the 1901 work in Havana, for the world to follow, wherever yellow fever exists. The following abstract of Surgeon-Major Gorgas' results was published in the _Practitioner_, May 1902, by Professor Hewlett, one of the foremost of English bacteriologists:-- "Commencing in February 1901, orders were issued that every suspected case of yellow fever should be screened with wire gauze at the public expense, so as to render the room or rooms mosquito-proof. All mosquitoes in the infected house and in contiguous houses were destroyed. After the middle of February, 100 men were employed in carrying out the destruction of the mosquito-larvæ in their breeding places, putting oil in the cesspools of all houses, clearing the streams, draining pools, and oiling the larger bodies of water. Up to June, quarantine was enforced, together with disinfection of the house and fomites. After that, however, rigid quarantine of the patient was stopped, and disinfection of fabrics and clothing ceased. It was merely required that the patient should be reported, his house placarded and screened, and a guard placed over each case to report how general sick-room sanitation was carried out, to see that the screen-door communicating with the screened part of the house was kept properly closed, and to see that communication with the sick-room was not too free, four or five non-immunes only being allowed in. _By the end of September, the last focus of the disease had been got rid of, and since then, up to the beginning of January, there has not been a single case._ Whereas, for the years since 1889, from 1st April to 1st December, yellow fever caused an average of 410.54 deaths, with a maximum of 1175 for 1896, and a minimum of 79 for 1899, _it caused in 1901 5 deaths only. In the months of October and November, when the disease has hitherto been exceedingly rife in Havana, there has not been a single case. For the first time in 150 years, Havana has been free from yellow fever._" Sir Patrick Manson, lecturing in America, last year, on tropical diseases, summed up the work as follows:--