The human species

by A. de Quatrefages

We are here, therefore, again led to considerations similar to those with which we have so often been brought in contact. We will therefore recall in a few words the general results of the preceding investigations.

1. The fundamental nature of all men is the same.

2. The formation of distinct races has been the sole cause of modifications in this fundamental nature of all human groups.

3. The several characters and special aptitudes which constitute a kind of acquired nature, have, in each of the groups, been developed under the influence of the conditions of life.

It is clear that when the disturbing action, the cause of disease, works upon the fundamental element, the same causes will produce fundamentally similar effects; when, on the contrary, this action is exercised upon the acquired and special element of each race, the same causes will produce different effects. In other words, unity of species and multiplicity of races involve the liability of all men to common diseases, which will, at most, vary as to accessory phenomena; but also allow the existence of diseases more or less peculiar to certain human groups.

Nevertheless, the great majority of diseases will be common to all men, and merely present modifications in the different groups. For example, one race may be either more liable to or more unsusceptible to certain affections than another.

Let me observe in passing, and without insisting upon facts known to all agriculturists and to all breeders, that similar phenomena are presented by the races of vegetable species which have long been under cultivation, and of animal species for centuries subject to domestication.

The propositions which I have just brought forward are the natural result of the facts to which I have already drawn attention, and of the principles admitted at the commencement of this book. They are in remarkable accordance with the results of experiment and observation.

III. It becomes more and more evident, from investigations which are daily increasing in number, that all human races are subject to almost every disease.

The Negro and the White have often been contrasted from a pathological point of view, and it has been stated that localities in which the latter succumb, are not unhealthy to the former. It is said that marsh fevers, dysentery, and abscess upon the liver, so feared by Europeans, do not attack the inhabitants of the coasts of Guinea, and the banks of the Senegal and the Gaboon. These are exaggerated statements which were reduced to their true value by the observations of Winterbottom, Oldfield, and others. More recent works confirm these earlier observations in every respect: “The Negro race,” says M. Berchon, “suffers from dysentery and abscess on the liver like the white race.... The deadly fevers, which, with the two diseases just mentioned, form the pathognomonical trilogy of Senegalese pathology, will first attack Europeans; but the Blacks are by no means exempt from them.”