208 



Mild acclimation (Groups II., III., IV.) . 48 cases — 92.2 per cent. 

 Acclimation with regular yellow fever, 



cured 3 „ — 5.9 „ 



Fatal yellow fever 1 „ — 1.9 „ 



52 



The next point was to obtain reliable data for comparison. I was 

 fortunate in receiving from two religious communities placed under my 

 medical charge the authorization to practise my inoculations on such 

 members as would be willing to submit to them. These communities are 

 those of the Jesuit and Carmelite Fathers, established in the city of 

 Havana. Their members are partially renewed almost every year by the 

 arrival of new-comers from Spain to substitute others who have resided 

 several years here. Since 1883, every year except 1885, I have inoculated 

 some of the new-comers, while others did not go through that ordeal. 

 During the period 1883-1890 the Jesuit Fathers have had thirty-six 

 inoculated and seven not, and the Carmelites had thirteen inoculated and 

 twenty-five not inoculated. Of the inoculated none have died of yellow 

 fever, whereas five of the non-inoculated have died of it (one Jesuit and 

 foiir Carmelites). After deducting from the inoculated thirteen cases still 

 under observation, we have thirty-three inoculated and thirty-three not 

 inoculated members of the same communities having arrived in the same 

 years as the former, leading the same life and exposed to the same 

 chances of infection. 



Inoculated Not inoculated 



Mild acclimation (Groups II., III., IV.). 31— 94 p. c. 21— 65 y 2 p. c. 



Acclimation with regular yellow fever cured. 2—6 „ 6 — 19 „ 



Died of yellow fever, none of the inoculated 



but of the non inoculated 5 — 151/2 „ 



33 32 



The conclusions which the above statistical results, together with the 

 •comparative observations, appear to justify are as follows: 



1. The inoculations with one or two recently contaminated mosqui- 

 toes, in the manner practised by ourselves, is free from danger, inasmuch 

 as the numerous trials which have been made have produced at most (in 

 -about 18 per cent, of our cases) a mild attack followed by immunity. 



2. We must attribute to the influence of the inoculations with con- 



