428 Proceedings of the Royal Physical Society. 
Tropical Africa his health remains good, in fact the heat seems 
to have a stimulating effect upon him. He does not suffer 
from the heat of the sun, and he forms a striking contrast to 
those emigrants who have resided in the same district for a 
considerable time. His work, be it mental or bodily, is 
performed with comparative ease. Soon, however, he begins 
to experience a marked change in the physical functions of 
his body. Its normal temperature is about 1° F. higher 
than it was in the temperate zone, his respirations are © 
considerably below the normal number, his heart’s action is 
increased in frequency, his digestive powers become weak- 
ened, his skin secretes far more freely and becomes somewhat 
swollen, his urine is lessened in quantity, and his nervous 
system is, to a greater or less extent, enfeebled. There is no 
doubt that very soon his mental and bodily powers become 
weakened, this being due to modified nutrition. He suffers 
from anemia and from a slightly congested liver. The 
anemia, if only slight, may be considered as prophylactic in 
character, and the congestion of the liver is only what might 
be expected on account of the increased work that that organ is 
compelled to perform. The resistance which an individual 
from the temperate zone can offer to these conditions depends 
on the height of the mean annual temperature, and also to 
some extent on its diurnal variation. If the temperature is 
high during the whole year, he is less able to withstand them 
than he would be were there marked differences in the 
temperature of the various seasons, or between that of night 
and day. This power of resistance may also be attained by a 
change of air at stated intervals to a place, either having a 
high altitude, or where marked variation in temperature 
occurs. The difficulty experienced in Africa at the present 
time is that comparatively few high altitude stations are 
known, and some considerable number of years must elapse 
before arrangements can be made to provide access to those 
areas where the emigrant, enervated by the heat and mois- 
_ ture, may seek the restoration provided by a residence at a 
high-level station. 
A word in passing as to the influence of the African 
climate upon women. Practically, although women do not 
