The influence of climate involves more than temperature. Stokvis, in a paper read before the Tenth International Medical Congress, at Berlin, on the comparative pathology of the human races with reference to the vital resistance of Europeans in tropical climates,[174] finds that the European immigrant in the tropics is assailed by two hostile forces: tropico-thermal and tropico-infectious agencies. The expression of innate racial peculiarities, like the variations of vegetable life and the varieties of animal life from effects of increased temperature, are such as occur in the inhabitants of temperate regions during the height of summer. Marestang and Eykman find that neither high temperature alone nor meteorological agencies, apart from other deleterious influences, can produce that impoverishment of blood called "tropical anæmia." Stokvis shows that the tropical European does not prove inferior to the aboriginal with respect to thermal agencies. He is less susceptible to chill than the native. Mortality statistics of respiratory organ affections are greater for the native. While the European suffers more from liver disease than the native, the latter is less addicted to alcoholic drinks and pork. The percentage of deaths from cases treated is, however, more than twice as great with the native as with the European. Variations of physiologic life under tropical thermal conditions have little to do with the race. The vital resistance of the immigrant European (the European transformed into a permanent high-summer man) is somewhat greater than that of the native races. Respecting the disease-producing effects of tropical infectious agencies, the experience of the last ten years (1880-90) is very different from that prior to 1860. Average annual death-rate per thousand:-- European Native Soldiers. Soldiers. { 1819-28 170·0 138·0 Dutch East India Army { 1869-78 60·4 38·7 { 1879-88 30·6 40·7 { 1800-28 84·6 18·03 { 1828-56 56·7 British India Army { 1869-78 19·37 { 1876-88 16·27 21·6 { 1820-36 121·00 30·0 British Army, Jamaica { 1879-88 11·02 11·62 These changes are the consequence of sound sanitation. "The fairest laurel practical hygiene may boast of to-day is, doubtless, the laurel acquired in ameliorating the sanitary conditions of the European soldiers in tropical climates." A century ago James Lind said, "Much more than to the climate you are indebted to your own ignorance and negligence for the disease from which you suffer in tropical climates."