214 TROPICAL MEDICINE AND HYGIENE 



uncertainty as to whether the mercury is regularly taken ; 

 (3) though the rate of absorption varies, still the mercury 

 is certainly absorbed. The disadvantage is that the 

 injection is slightly painful, that a certain amount of 

 induration and tenderness may be left, and that, rarely, 

 abscesses may form. Much depends on the confidence 

 the natives have in their medical officer. 



Salvarsan, or neosalvarsan, especially when injected 

 intravenously, have a rapid effect even when mercury 

 has had little effect. The early hopes that one or two 

 injections would result in a permanent " cure " have not 

 been realized, and it is advisable after treatment with 

 salvarsan to continue the use of mercury for at least three 

 months even if a negative Wassermann reaction is 

 obtained. 



Congenital syphilis is not common, but it is probable 

 that syphilis is an important factor in the causation of the 

 large number of abortions and stillbirths, and is respon- 

 sible for much of the sterility of the native. It must be 

 remembered that the negro is fertile earlier in life, when 

 the effects of the virus are most marked, but ceases to be 

 fertile in many cases at an earlier age than the European, 

 and therefore has few children at ages when the most 

 fatal effects of the disease are less likely to occur. 



Prophylaxis. Prophylactic measures are similar to 

 those required in England. The local labour supply 

 is usually insufficient for the large plantations, mines and 

 other enterprises of Europeans. Large numbers of men 

 are therefore, imported from other districts and countries 

 or attracted by the superior rate of pay. Men as a rule 

 come in great excess of women, who are of less value 

 as labourers, and many of these women are or become 

 prostitutes. With such gangs of men, whether soldiers 

 or labourers on plantations, it is often possible to find 

 the infecting agent or agents. A certain proportion of 

 women should always be imported with the men, and 

 this is arranged for in Indian immigration ordinances. 

 Every encouragement should be given to men bringing 



