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Popular Science Monthly/Volume 48/April 1896/Acclimatization II

< Popular Science Monthly‎ | Volume 48‎ | April 1896




WHAT is the first effect of a tropical climate upon the human body and its functions?[1] The respiration becomes more rapid for a time, although it soon tends toward the normal;[2] the pulse beats more quickly;[3] the appetite is stimulated;[4] and a surexcitation of the kidneys[5] and the sexual organs ensues;[6] the individual as a rule becomes thinner;[7] the liver tends to increase in size, which is perhaps the cause of a certain sallowness of skin;[8] and in females menstruation is often disturbed, the age of puberty being sooner reached.[9] A very important change, which has not perhaps been fully investigated as yet, is a temporary rise of temperature, which often lasts for some time after the individual leaves the tropics.[10] Sir Humphry Davy was the first to note, on a voyage to Ceylon, that the temperature of travelers tended to rise in this way[11]and Dr. Guegnen confirms his conclusions, although he shows that the rise is less than had been supposed.[12] Dr. Maurel concludes that it varies from 0·3 to 0·5.[13] Observations on Europeans between Khartoum and the equator showed that for those who had been there less than two years the average was 99·5°, or nearly a degree above the normal. Those who had been there longer than four years exhibited a lower temperature of 99·1°, still a half degree over the average in Europe.[14]

It is not impossible that these delicate variations of temperature may bear some relation to the racial pathological predispositions which we have noted, as well as to the liability of the newcomer in the tropics to contract fevers and other zymotic diseases from which the natives and the fully acclimated whites are immune.[15] Darwin indirectly hinted at such a solution many years ago, and suggested at the same time a study of the relation of the complexion to immunity from fevers. But no one appears to have followed it up.[16]The recent development of the science of hydrotherapeutics certainly points to this conclusion. Several observers have already noted a permanent difference in the normal mouth temperature of the different races. Glogner has shown that the temperature of the Malay is slightly lower than that of Europeans,[17] the brown skin radiating heat more freely.[18] The Mongolian race more nearly approaches the European than does the negro, whose norm is considerably lower.[19] Dr. Felkin[20] gives observations to show that the average mouth temperature of six hundred negroes between the equator and 10° north latitude was 97·8° F., the European normal being 98·6°. Higher than either were the Soudanese, whose average was 99°. In the European coming to the tropics, therefore, the temporary rise of body temperature increases still more the difference between his own and the indigenous normal in most cases. It has, indeed, been suggested that this is the cause of malarial fever in the tropics, but the matter has never been fully investigated, especially in its relation to other zymotic diseases.

Among animals the connection between minute variations of body temperature and the liability to contract diseases due to micro-organisms is well established. A fowl, whose normal temperature is considerably above that of the horse, the dog, or the rabbit, is immune from splenic fever, to which these other animals are liable; and yet Pasteur, by reducing its blood heat to their level, by immersing its legs in cold water, was able successfully to inoculate it with the anthrax bacillus.[21] And other fowls were cured of the fever so contracted by artificially raising their temperature to a point at which the bacillus could no longer thrive. For the same reason tuberculosis does not flourish in frogs or other cold-blooded animals, unless their blood temperature is sufficiently raised to permit of its germination. It is too early to assert that the same law will apply to the "traumatic" diseases of the tropics; but one point is certain, that newcomers in those regions are particularly liable to zymotic diseases during that period when their temperature is most above the native normal; and that immunity from attack, or at least a more benign form of the disorder, often comes with that fall in temperature which is perhaps the surest sign of true acclimatization. Finally, it will be noted that even when this temperature falls once more to the European normal, it is still higher than that of the natives. And if there were any truth in this theory, the perfect accommodation to the environment which the natives of the tropics enjoy, would be attained only when the normal temperature of the European had been reduced to their level. But the persistence of physiological ethnic traits is a well-known fact; the Hindu to-day, despite his long sojourn in the tropics, has a temperature merely reduced to his own racial normal—to reduce it still further to the level of the negro would require ages of time.[22]

Acclimatization in this physiological sense, of a gradual approach and approximation to the normal type of the natives, must of necessity be an exceedingly slow process, involving many generations of men. Yet in every respect except of temperature it appears that the first effects of a sojourn in the tropics is to induce symptoms which point toward the peculiarities of the native type. Thus the increase in the size of the liver indicates the operation of those causes which have finally made the negro's liver normally larger than that of the European.[23] The only present difficulty is that an unusual strain is suddenly put upon the various organs in this process of gradual adaptation which is often too severe; as, for example, the high mortality among Europeans from derangement of the liver, such as hepatitis, bilious fever, abscesses, and the like, which indicates that some physiological change has taken place which has entailed an excessive demand upon the activities of this organ. Similarly the extreme liability of the negro to disases of the lungs in the temperate zone may be due to his lack of physiological accommodation to those circumstances which have in hundreds of generations produced the European type. To expect that man can in a single generation compass the ends which Nature takes an age to perform is the height of folly. The exact nature of the physiological processes induced by the tropics is, however, so imperfectly known that we must in general rely upon concrete experience for our further conclusions.

Results of Hygiene.—Hygiene and sanitation have accomplished wonderful results in assisting the individual to withstand those immediate effects of climatic change which, as we have said, are so often fatal.[24] The yearly loss at one time in India was eighty for each regiment of one thousand men. In 1856 it had been reduced to sixty-nine; from 1870 to 1879 it ranged about sixty-two; and in 1888 the annual loss was only fifty, including deaths and invaliding.[25] The loss in Cochin-China per regiment was one hundred and fifteen in 1861; the actual deaths have now been reduced to twenty-two, although a much higher figure would be needed to include invaliding. The terrific annual loss of one hundred and forty-eight per thousand in Senegal from 1832 to 1837 is now reduced to about seventy-three. In this last case, however, one hundred and fifty per thousand are returned for sickness every year.[26] A large proportion of these would undoubtedly die if not removed immediately. One may indeed be hopeful from such results that, with further advance in the science of prevention, these figures may be yet further reduced. The system of vacations,[27] of strict regulation of diet, the avoidance of excessive fatigue and exposure, and especially of all forms of agricultural labor, and the extension of the hill-station system, will do much in this respect; so that it is conceded by most candid observers that, with few exceptions, such as Cochin-China and the coast of Africa, robust individuals by great care stand a fair chance of good health in the tropics. Nevertheless, this should never be allowed to conceal the real fact that the English to-day are no nearer true acclimatization in India than they were in 1840. To tolerate a climate is one thing, to become independent of it is quite a different matter. The securing of a permanent footing in the tropics depends upon factors of a totally different nature.

Fertility.—Passing now from the consideration of the individual to that of the race, the keynote of the matter rests in the much-controverted question of the influence of change of climate upon fertility. For, however well the individual may be enabled, by artificial means or otherwise, to exist, the race will never accommodate itself permanently unless the birth-rate exceeds the death-rate.[28] Here we must first carefully eliminate the effects of ethnic crosses with natives of the tropics; for a fatal mistake of many observers has been the neglect to distinguish the possible sterility induced by intermixtures of race from that caused by a change of climate and of life conditions; or statements of one have been accepted by tyros as equivalent to the other. It has been confidently asserted for so many years that sterility of the white race ensues after three generations in the tropics that it has become a household word in anthropology.[29]

The result of comparative study of the lower forms of life is suggestive in this connection.[30] With plants and animals a sudden change of habitat will often produce a temporary sterility, which disappears only after a series of chance variations. The chrysanthemum remained infertile for sixty years after its introduction into France from China, so that continued importation of the seed was necessary. Finally, in 1852 a few plants developed seeds; and from these others were raised, until to-day the species is self-sustaining in Europe. A similar experience with corn at Sierra Leone, with the goose at Bogotá, and European poultry in America, is instanced by De Quatrefages.[31] His rather optimistic argument with regard to the future of acclimatization is based, indeed, upon the study of animals and plants, rather than of man. He reasons by analogy that if fertility becomes re-established by spontaneous variation in this sphere, it may be likewise affirmed to be true for man, thus giving countenance to the view that climatic changes do indeed produce infertility.

Despite the authorities who hold on general principles that sterility in man follows—or at least that it ought to follow—a sudden change of climate, direct proof for it is very hard to find. Broca has indeed affirmed that the Mamelukes in Egypt became infertile for that reason;[32] but in his case, as in all others, no attempt is made to eliminate a number of other factors. Jousset declares, on the contrary, that no direct effect upon fecundity can be traced to climate.[33] Dr. Fritsche concedes that, although sterility may result, there is as yet no direct evidence to prove it.[34] The difficulty, it will be observed, is to eliminate the effects of crossing with the natives, or else of marriage with newly arrived immigrants. A physician of twenty-seven years' experience in the Dutch Indies has never known a European family to keep its blood unmixed in this way for the necessary period of three generations. Only one example of pure isolation is known, in the island of Kisser, and sterility there is by no means certain.[35]

sterility from climate as a single cause in this part of the world, then, can neither be affirmed nor denied, from utter lack of evidence.[36]

On the contrary, a number of examples of continued fertility might be given. Brace affirms the Jews to be fertile even in Cochin-China,[37] and Joest says that Europeans in Africa often bear children.[38] The Spanish women in Guayaquil, on the authority of Dr. Spruce, in a climate where the temperature is seldom below 83° F., and in the complete absence of intermarriage with the natives, are the finest along the coast; and the white population is exceedingly prolific[39] The experience of Algeria, so far at least as heat is concerned, seems to bear out the same conclusion, the birth-rate being higher even than in France.[40] De Quatrefages, despite his inference of a temporary infertility, certainly takes a hopeful view for the other French colonies.[41] Some remarkable examples of fecundity, indeed, are not lacking. Some years ago, an English woman, never out of India, not even taking a vacation in the hills, died at the age of ninety-seven, leaving eighteen children.[42] Tilt, however, denies that the English in general can ever become acclimated there.[43] Sterility, of course, while most important, is not the only element in the acclimatization of the race. Even if we could affirm that sterility did not result, the perpetuation of a people in the tropics would not necessarily follow; for the mother may seldom survive childbirth, as in the East Indies and on the Zambesi,[44] or the children may seldom survive,[45] the age of six being often a critical period.[46] But these facts have no connection with sterility or the reverse, although they may produce the same negative result in the end. The final word upon this subject awaits more carefully sifted evidence than any we now possess.

Comparative Aptitudes of European Nations.—The future political destiny of Africa is not unlikely to be dominated by a remarkable fact—namely, the severe handicap against which the Teutonic stock, and especially the Anglo-Saxon branch, struggles in the attempt permanently to colonize the tropics. And this is peculiarly unfortunate, since these are the very peoples who find population pressing most severely upon the soil at home.[47] The Latin nations, of course, are the ones who lay most stress upon this comparative disability of their rivals; but in justice to the French, it must be added that they have generally recognized that the Spaniards and Italians possess as great an advantage over them as they in turn do over the Germans.[48] The experience of Algeria affords a good illustration of this point. The year 1854 marks the first excess of births over deaths in this colony; and the following table shows the relative disabilities of the Europeans for 1855-'56:[49]

Births pro mille. Deaths pro mille.
Spaniards 46 30
Maltese 44 30
Italians 39 28
French 41 43
Germans 31 56

Dr. Ricoux[50] gives the following death rates per thousand for children under one year: Spaniards, 180; Maltese, 178; Italians, 194; French, 225·2; and Germans, 273. This disability of the Germans is confessed by all their most able and candid authorities.[51] All writers, even in France, acknowledge that the Mediterranean natives possess a peculiar aptitude in this respect.[52] Moreover, the French nation is further divided against itself. That the Provençals—the offshoots of the Mediterranean branch of the Aryan stock—succeed better than the people of the Paris basin in the tropics is generally conceded;[53] and the bulk of French emigration to-day comes from the Rhone Valley, Corsica, and Provence.[54] This makes the fact still more curious that these same Provençals endured the hardships of Napoleon's Moscow campaign far better than their comrades from Normandy and Champagne.[55] Can it, indeed, be due to an admixture of Semitic blood, as Wallace suggests?

This disability of the Anglo-Saxon stock does not seem to indicate any less vitality, but rather the reverse.[56] The Crimean War apparently showed that the English possessed a peculiar advantage over the French in their ability to recover speedily from severe wounds.[57] In fact, the mortality after capital operations in English hospitals is only about half that among the French.[58] We have already observed that primitive peoples, while showing a relative immunity from septic disorders, still remain peculiarly sensitive to all changes of climate.[59] And the case of the Anglo-Saxon stock is analogous to it in this respect, having a higher recuperative power conjoined to disability in becoming acclimatized.[60] This is undoubtedly in part due to national habits, but it also appears to be rooted in race. In peopling the new lands of the earth, therefore, we observe a curious complication; for it is precisely those people who need the colonies most, and who are bending all their political energies to that end, who labor under the severest disabilities. A popular opinion is abroad that Africa is to be dominated by the English and German nations.[61] If there be any virtue in prediction, it would rather appear that their activities will be less successful as soon as the pioneering stage gives way to the necessity for actual colonists, who with their families are to live, labor, and propagate in the new lands.

Summarizing the views of authorities upon this subject, the almost universal opinion seems to be that true colonization in the tropics by the white race is impossible.[62] The only writers who express themselves favorably are Crawford,[63] whose hopes for India have certainly not been fulfilled; Armand[64] and Rattray,[65] Dr. Livingstone and Bishop Hannington,[66] and the physicians assembled at the Medical Congress at Berlin in 1890,[67] with the Society for the Advancement of Medical Science in the Dutch Indian Settlements.[68] All these authorities may now be classed as antiquated, except the last, and moreover the first one represents that nation which is notoriously unsuccessful in acclimatization. The opinion of the Dutch physicians who have been fairly successful may be met by as good testimony from their own number on the opposite side.

Authorities in favor of the view that complete acclimatization of Europeans in the tropics is impossible might be multiplied indefinitely. Among the earlier writers of this opinion are Knox,[69] Prichard,[70] Dr. Hunt,[71] and Sir Ranald Martin.[72] The best German authority concedes it, including Virchow, Fritsche, Joest, Fischer,[73] with Buchner[74] and Hirsch.[75] The French, who have studied it more scientifically than any other nation, hold to this opinion with no exception.[76] Jousset declares that recruiting stations never effect a permanent recovery, the only remedy being to leave the tropics altogether.[77] This opinion is also shared by many of the Dutch, who dissent from the favorable views of their countrymen already quoted.[78] The English writers of this opinion include Ravenstein,[79] Sir William Moore,[80] and Tilt.[81] Dr. Felkin alone holds to a slightly more favorable view of colonization in Africa, although he qualifies it by requiring an unlimited amount of time; and he finds comfort in the thought that Central Africa is no worse than India. He finally concedes, however, that in this latter colony the hill districts are the only ones where the English can remain in health.[82] For some years the hopes for Africa as a field for colonization were based upon the altitude of the inland plateau. But expert opinion on this seems to show that, with the sole exception of Matabeleland, the country is impossible for European colonists.[83] And even Mr. Stanley declares that cautious pioneering is all that can be expected for the future in the Congo basin—that colonization was never anticipated at all.[84] In the face of such testimony there can be but one conclusion: to urge the emigration of women, children, or of any save those in the most robust health to the tropics may not be to murder in the first degree, but it should be classed, to put it mildly, as incitement to it.

It must not be understood that by this is meant that the white man can not live in the tropics. Hygienic precautions and great care can often render a prolonged sojourn in these regions perfectly harmless. But, as Mr. Wallace observes, the Englishman who can spend a summer in Rome in safety only by sleeping in a tower and by never venturing forth at night, can not be truly said to be acclimated. A colony can never approximate even to the civilization of Europe until it can abolish or assimilate the native servile population; and yet, one of the many things which are expressly forbidden to all colonists in the tropics is agricultural labor. It would be a waste of energy to give citations to prove this, for every work on acclimatization insists upon the necessity of this precaution. Let it be understood, then, that a colonial policy in the tropics means a permanent servile native population, which is manifestly inconsistent with political independence, or with any approach to republican institutions.


Such being our conclusions from a comparison of authorities, what shall we say about the broader question of original racial acclimatization? And what policy, if any, should be modeled upon the theories with regard to the way in which this undisputed operation once took place—for, as we have said, the substantial unity of the human race followed by extensive migrations is an accepted fact. Even in the absence of direct proof, to deny it would be to neglect all the evidence for the same phenomenon among plants and animals so ably set forth by Wallace, Agassiz, Drude, and other writers. Fortunately, however, the researches of ethnologists to-day are continually bringing new evidence to show that such widespread migration has indeed taken place. Two radically different policies are advocated by the adherents of one or the other of the two opposing factions in biological theory. For accommodation to climatic conditions may take place either by variation and natural selection or by habitual adaptation transmitted by inheritance.[85] Weissmann,[86] Wallace, Quatrefages,[87] and apparently Dr. Brinton,[88] rely upon natural selection, which they assert, directly or by inference, takes place in the following way: A large body of men (plants or animals) is transported to the new habitat at once—the larger the number the better—from which by elimination a few fortunate variations survive. Thus, after a long time, and enormous sacrifice of life, a new type, immune to some degree, becomes established. All that the state need do, therefore, is to keep up the supply of immigrants long enough, and leave the climate to do the rest.[89]

What state policy may we adopt if we hold to the biological theory of adaptation and heredity? This school includes Virchow and Buchner,[90] who firmly defended it at the Natural Science Congress at Strasburg, and by Jousset.[91] Their policy would be to imitate the operations of natural ethnic migrations; they would rely upon the utilization of the natural aptitudes of various nationalities, which we have mentioned—perhaps themselves the fruit of ages of sojourn in certain climates—until finally a great drifting movement toward the equator would take place.[92] In other words, the peoples of the Mediterranean basin, learning of their aptitude for a southward migration, would perhaps move to Algeria, displacing the people of the Soudan and the Semitic stocks toward the equator. To fill the place thus left vacant, the people of northern France slowly drift to the Rhone Valley and Provence for a generation or two, and their place is taken by Germans and Belgians.

That this is a tendency at the present time can not be doubted.[93] Each generation adapting itself quietly would produce succeeding ones with an inherited immunity. Unfortunately, this most reasonable let-alone policy has two fatal objections: in the first place, it requires a policy of noninterference; and, more potent still, it absolutely neglects the political factor. To suppose that France would quietly allow her people to be dispossessed by Germans, even though she aided her colonial policy thereby, or that Germany would quietly leave Africa to her Gallic neighbor, is not to be supposed for a moment. Nevertheless, it will be probably the only policy which will finally produce a new immune type in the regions of the equator. Of course, England is by fate condemned to follow the first policy we have outlined. France, indeed, is the only one of the European states which extends over the two contrasted European climates; a large measure of her success is probably due to that fact; while all the nations north of the Alps must traverse her territory or that of Italy on the way to these newly discovered lands. Great political results are therefore not impossible, if the prognosis we have indicated prove to be correct. At all events, enough has perhaps been said to show that great problems for science remain to be solved before the statesman can safely proceed to people those tropical regions of the earth so lately apportioned among European states.


Armand. Traité de Climatologie, Paris, 1873.
Bastian, a. Klima und Akklimatization, Berlin. Very diffuse.
Bertillon, Dr. Acclimatement and Colonization in the Dictionnaire encyclopédique des Sciences médicales. Also in Bulletin de la Société d'Anthropologie de Paris, 1864, pp. 519, 578.
Berenger-Feraud,Dr. Traité des Maladies Européennes au Sénégal, Paris, 1875.
Bordier, Dr. A. La Géographic médicale. La Colonisation scientifique. Bibliothèque des Sciences contemporaines, Paris, 1884.
Boudin, J. Ch. M. Traité de Géographie et de Statistique médicale, Paris, 1857.
Chervin, Dr. A. Géographie médicale de la France, in Annales dc Demographie, iv, p. 10.
Clarke, Dr. R. In Journal of the Royal Statistical Society, London, xix, p. 60.
Davidson, Dr. A. Geographical Pathology, Edinburgh and London, 1892.
Felkin, Dr. R. W. On the Geographical Distribution of Some Tropical Diseases and their Relation to Physical Phenomena, London, 1889.—In Scottish Geographical Magazine, ii, p. 647.—In Proceedings of the British Association for the Advancement of Science, 1886, p. 729.
Fuchs, Dr. C. Medicinische Geographie, 1853.
Hirsch, Dr. A. Handbuch der historisch-geographischen Pathologic, 2te Auflage, 1881, translated. In Verhandlungen der Berliner Gesellschaft für Anthropologie, etc., 1886, p. 155.
Hunt, Dr. J. Ethno-Climatology, in Proceedings of the British Association for the Advancement of Science, 1861, p. 129; or Transactions of the Ethnological Society, London, ii, p. 50.
Jousset, Dr. A. Traité de l'Acclimatement, Paris, 1884. One of the best.
Kelsch and Kiener. Traités des Maladies des Pays chauds, Paris, 1889.
Lombard, Dr. H. C. Traité de Climatologie médicale, 4 vols., Paris, 1877.
Macculloch. Statistical Reports on the Sickness and Mortality among the Troops, London, 1840.
Maehly. Ueber Akklimatization, Special Heft der Deutsche Kolonialzeitung für medicinische Geographie, Klimatologie und Tropen Hygiene. Berlin, 1886.
Montano, Dr. J. In Bulletin de la Société de Géographie de Paris, 1878, p. 418.
Muhry. Geographische Verhältnisse der Krankheiten, 1876.
Orgeas, Dr. J. La Pathologie des Races Humaines, Paris, 1886.
Quatrefages, A. De. L'Espèce Humaine, liv. vi, Paris. Translated 1890.
Rey, Dr. H. In Bulletin de la Société de Geographie de Paris, 1878, pp. 38, 155, 229.
Rochard. Acclimatement, in Nouveau Dictionnaire de Médecine et de Chirurgie pratique, Paris, 1879.
Sormani. La Géographie médicale de l'ltalie, and in Annales de Demographie, v, p. 184.
St. Vel. Dr. O. Hygiène des Européens dans les Climates tropicaux, des Creoles et des Races colorées dans les Pays tempérés, Paris, 1872.
Stokvis. Ueber Vergleichende der Rassenpathologie. Verh. des X. inter. med. Congress, in Berlin, 1890.
Sykes, Dr. In Journal of the Royal Statistical Society, London, ix, p. 157; x, p. 100; xiv, p. 109; xv, p. 100.
Thevenot. Maladies des Pays chauds, Paris, 1870.
Treille. In Proceedings of the International Congress of Demography and Hygiene, Vienna, ix, 1887.
Van Overbeek de Meyer. Ueber den Einfluss der tropischen Klimas auf Eiugewanderte aus höheren Breiten. Verb, des X. inter, med. Congress. in Berlin, 1890.
Virchow, R. In Verhandlungen der Gesellschaft für Anthropologie, Ethnologie und Urgeschichte, Berlin, 1885, p. 202 et seq.
Wallace, A. R. Acclimatization, in the Encyclopædia Britannica.

  1. This general subject is somewhat technically discussed in Revue d'Anthropologie, new series, ii, p. 135.
  2. Jousset, op. cit., p. 160. Also Bulletin de la Société de Géographie de Paris, 1878, p. 427.
  3. Ibid., p. 197.
  4. Ibid., pp. 208, 211.
  5. Ibid., p. 221.
  6. Ibid., 229.
  7. Ibid., p. 139. Healthy Europeans in the tropics are lighter in weight than the same class at home (Archiv für pathologische Anatomie, etc., cxix, p. 254).
  8. Hirsch, op. cit., iii, p. 388; cf. Peschel, Races of Man, p. 92.
  9. This well-known fact is clearly shown by statistics in Revue d'Anthropologie, second series, v, p. 373.
  10. Jousset, op. cit., pp. 201, 207, 259, 391.
  11. Proceedings of the Royal Society, London, 1814, civ, 1825. Other references in Bulletin de la Société d'Anthropologie, Paris, 1884, p. 374.
  12. Archives de Médecine navale, January, 1878.
  13. Bulletin de la Société d'Anthropologie, 1884, pp. 375 et seq.
  14. Proceedings of the British Association for the Advancement of Science, 1889, p. 787.
  15. The true creole, for example, is immune from yellow fever.
  16. Descent of Man, i, p. 233 et seq.
  17. Archiv für pathologische Anatomie und Physiologic und für klinische Medicin, cxvi, p. 540.
  18. Ibid., cxix, p. 256. Contains many tables of results.
  19. Bulletin de la Société d'Anthropologie, Paris, 1884, p. 380. Jousset affirms the same quite independently, op. cit., p. 383.
  20. Proceedings of the British Association for the Advancement of Science, 1889, p. 787.
  21. Sutton, Evolution and Disease. London, 1890, p. 253.
  22. Jousset, op. cit., p. 382.
  23. This is suggested by Bastian in Zeitschrift für Ethnologie, Part I, 1869; vide also J. R. Mayer, Die Mechanik der Wärme, p. 97 (Stuttgart, 1867), and Jousset, p. 108. The physiological characteristics of the negro are well described by Jousset as follows: A weakly developed chest (p. 85), less respiratory power and lung capacity (p. 88), more rapid pulse (p. 95), diminished muscular tension (p. 100), lower temperature (p. 107), less perspiration (p. Ill), and a tendency toward slimness (p. 139). The lessened vitality and power of endurance is also to be noted (p. 144). Pruner Bey confirms these results in his studies of the vascular system of the negro. Vide also Quatrefages, op. cit., p. 407. Drs. Baxter and Gould, in their studies on our soldiers during the civil war, confirm this fully. (Investigations in the Military and Anthropological Statistics of American Soldiers, Cambridge, 1869; and Medical Statistics of the Provost-Marshal General's Bureau.)
  24. Discussed by Hunt, op. cit., p. 140, and by Dr. Montano, op. cit., p. 8 et seq.; by Davidson, op. cit., for India; and by Dr. Farr, in Journal of the Royal Statistical Society, xxiv, p. 472. Vide also, for statistical information, ibid., iv, p. 1; viii, pp. 77, 193; ix, p. 157; X, p. 100; xiv, p. 109; xv, p. 100. Tables of the comparative mortality of British troops in various countries are conveniently given in Revue d'Anthropologie, new series, iv, p. 175. Macculloch, Statistical Report on the Sickness and Mortality of Troops, London, 1840, gives a vast amount of information.
  25. Scottish Geographical Magazine, vii, p. 647.
  26. Revue d'Anthropologie, third series, iv, p. 346.
  27. In Cochin China one year in three is the allowance. The improvement in Senegal is largely due to the brief sojourn of the troops, who are relieved at short intervals. This system now prevails also in India, in sharp contrast to the old practice of keeping the soldiers there for long terms, in the hope of forcing acclimatization in that way.
  28. Vide remarks of Prof. Virchow on this point in Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, p. 202.
  29. Many examples of acceptance of this theory of infertility will be found in popular works. Pearson (National Life and Character, p. 89) bases his whole argument upon it Prof. Virchow even asserts it to be true in Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, p. 213. It was at the bottom of the exploded theory of Knox and Brace with respect to the decreasing birth-rate in America. Cf. Mémoires de la Société d'Anthropologie, iii, p. 25.
  30. Discussed by Wallace in Encyclopædia Britannica. Also for forest trees in Kirchhoff's Forschungen, iii, p. 28 et seq.
  31. Op. cit., p. 225. Many other examples are given. Wallace (op. cit.) gives the interesting case of the acclimatization of wheat north of the Great Wall by the Emperor of China.
  32. Human Hybridity. Cf. the case of the Creoles in the island of St. Louis, cited in Revue d'Anthropologie, new series, v, p. 30 et seq.
  33. Op. it., p. 231. The superior health of women, due to less exposure, has already been noted.
  34. Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, p. 258.
  35. Ibid., 1886, p. 89.
  36. Verhandlungen der Berliner Gesellschaft für Anthropologie, 1886, p. 92.
  37. Wallace, op. cit.
  38. Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, p. 473.
  39. Wallace, op. cit.
  40. Levasseur, La Population Française, iii, p. 432.
  41. Op. cit, p. 231.
  42. Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, p. 319.
  43. Health in India for British Women.
  44. Peschel, Wallace, Quatrefages.
  45. Jousset, op. cit., p. 314. Cf. Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, p. 258, on Egypt.
  46. Wallace, op. cit.
  47. Levasseur, La Population Française, iii, p. 432.
  48. Revue d'Anthropologie, second series, viii, p. 190.
  49. Bulletin de la Société d'Anthropologie, 1886, p. 269; cf. L'Anthropologie, vi, p. 120. The small number of Germans present weakens the force of the evidence somewhat.
  50. Annales de Demographie, vi, p. 14. Cf. Quatrefages, op. cit., p. 230, and Bordier, Colonization, p. 184. The only north Europeans ever successful are the Dutch in South Africa and in the East Indies.
  51. Ratzel, Anthropo-Geographie, i, p. 304; Virchow, Fritsche, and Joest in Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, pp. 211, 474, etc. It will have been noted that nearly all references in German fall within the years 1885-'87. The question drifted into politics—out of the hands of scientists into those of pamphleteers. Vide Max Nordau, Rabies Africana, in Asiatic Quarterly Review, second series, ii, p. 76; and G. A. Fischer, Mehr Licht im dunkeln Welttbeil, Berlin, 1886. A blue-book on the subject was promised (Verhandlungen der Berliner Gescllschaft, 1886, p. 87), but the attention of the Colonial Society was for some reason diverted. Tropical hygiene was fully discussed, but the broader scientific aspect of the matter was neglected (Verhandlungen, 1889, p. 732). As late as 1890 no definite government report had been issued except Mähly's work. The Germans apparently do not dare to handle it without gloves, and their views are unique in their optimism (Kohlstock in Science, 1891, p. 3; and Finckeluburg in Handbuch der Staatswissenschaft).
  52. Ratzel, loc. cit.; Bulletin of the American Geographical Society, 1883, No. 2; Jousset, p. 292; Montano, pp. 444, 446; Felkin, in Scottish Geographical Magazine, ii, p. 52, and in British Association for the Advancement of Science, 1886, p. 730; Levasseur, op. cit., ii, p. 431; and Bordier, Colonization, pp. 185, 493.
  53. Quatrefages, op. cit., p. 230; Jousset, p. 192; Montano, p. 449; and Levasseur, ii, p. 431.
  54. L'Anthropologie, v, p. 253.
  55. Bulletin de la Société d'Anthropologie, i, p. 326; and Revue d'Anthropologie, new series, i, p. 76.
  56. Dr. Beddoe, Races of Britain, p. 224, gives some exceedingly interesting observations upon this point.
  57. Revue d'Anthropologie, new series, i, p. 76 et seq.
  58. Topinard, Elements, p. 412.
  59. The stupendous failure of the project of colonizing the State of Durango in Mexico with negroes from the United States is a case in point. Vide letter in Boston Transcript, dated Mexico, August 11, 1895. Dr. Brinton, in Races and Peoples, p. 40, gives some valuable references upon this point.
  60. Dr. Montano, p. 447; Revue d'Anthropologie, second series, v, 74: "The Anglo-Saxon race is least apt of all in accommodating itself to warm climates." This fact is reluctantly admitted by Dr. Felkin and other English authorities as well.
  61. Vide typical editorial in Boston Herald, May 2, 1895.
  62. The most definite as well as the latest expression of expert opinion fully agrees with this. Vide Proceedings of the International Geographical Congress at London, 1895.
  63. Transactions of the Ethnological Society, London, new series, i, p. 89.
  64. Traité de Climatologie, Paris, 1873.
  65. Jousset, p. 426.
  66. Scottish Geographical Magazine, vii, 647.
  67. Proceedings of the Royal Geographical Society, January, 1891, p. 80.
  68. Referred to in the Proceedings of the Seventh International Congress of Demography and Hygiene, London, xi, p. 170.
  69. Quatrefages, p. 229.
  70. Jousset, p. 426.
  71. Loc. cit., p. 135; other opinions of early writers are here given as well.
  72. Encyclopædia Britannica, Acclimatization.
  73. Scottish Geographical Magazine, vii, p. 647, and Verhandlungen der Berliner Gesellschaft für Anthropologie, 1885, pp. 210, 257, 474. Prof. Virchow distinguishes between malaria and climate, which is generally a distinction without a difference in the tropics.
  74. Correspondenzblatt, xviii, p. 17.
  75. Verhandlungen, 1886, p. 164.
  76. Dr. Rey, op. cit.; Boudin, Bulletin de la Société d'Anthropologie, 1864, pp. 780 and 828; Legoyt, Jousset, p. 426; Bertillon, Bulletin de la Société d'Anthropologie, 1864, pp. 519 and 578; Bordier, Colonization scientifique, pp. 184, 397, 472; and Revue d'Anthropologie, third series, i, pp. 667, 672.
  77. Jousset, p. 434.
  78. Dr. Van der Burg in Transactions of the Seventh International Congress of Demography and Hygiene, p. 170. After all precautions have been taken, "such a settlement ought to be continually supported by new supplies from the European continent for many, possibly for hundreds of years, in order to have a chance of healthy existence."
  79. Proceedings of the Royal Geographical Society, January, 1891, p. 31, and Proceeding of the British Association for the Advancement of Science, 1894.
  80. Edinburgh Medical Journal, xxxi, part ii, p. 852.
  81. Transactions of the Seventh International Congress of Demography and Hygiene.
  82. Proceedings of the British Association for the Advancement of Science, 1886, p. 729.
  83. Proceedings of the Royal Geographical Society, January, 1891, p. 31, and Transactions of the Seventh International Congress of Demography and Hygiene, p. 178.
  84. Proceedings of the International Geographical Congress, London, 1895. Since this was written new and important evidence to the same end is given in the Scottish Geographical Magazine, xi, p. 512.
  85. Discussed by Wallace in Encyclopædia Britannica.
  86. Correspondenzblait der deutschen Gesellschaft für Anthropologie, xviii, 1887, p. 18.
  87. Op. cit.
  88. Op. cit., p. 283, seems to follow De Quatrefages.
  89. This would be the policy outlined by Dr. Van der Burg, quoted in note ante.
  90. Correspondenzblatt, 1887, p. 18.
  91. Op. cit, p. 245 outlined in his general argument. Vide note ante.
  92. This view is expressed by Ravenstein (Proceedings of the Royal Geographical Society, 1891, p. 35 et seq.) and by Dr. Felkin (British Association for the Advancement of Science, 1886, p. 730), who do not, however, seem to appreciate the biological analogies of their mode of treatment.
  93. Map of foreigners in France in Bulletin de l'Institut international de statisque, iii trois liv., 1888, p. 36; this fact is noticeably prominent. The destination of French emigrants is given in l'Anthropologie, v, p. 253. Vide also Transactions of the International Congress of Demography and Hygiene, p. 131 et seq.
  94. Other and more technical articles upon the subject have been referred to in footnotes, such as Archives de Médecine navale, Bulletin de la Société de l'Acclimatement de Paris, Archiv für pathologische Anatomie und Physiologie, etc. Maps of the distribution of certain diseases will be found in Gerland's Atlas der Völkerkunde and in the works of Drs. Chervin, Felkin, Lombard, and Sormani.