Malebranch's search after truth, or, A treatise of the nature of the humane mind and of its management for avoiding error in the sciences : vol I : done out of French from the last edition.

CHAP. III.

That the Air one breaths, causes likewise some change in the Spirits.

THE second general Cause of the changes which happens in the Animal Spirits, is the Air we breath; for, altho' it does immediately make as sensi∣ble impressions as the Chyle, nevertheless, in some time, it produces the same effect as the Juice of our Food does presently. This Air enters from Branches of the Wind-pipe into that of the Venous Artery, and from thence it mingles it self, and ferments with the rest of the Blood in the Heart; and according to its particular disposition, and that of the Blood, it pro∣duces great changes in the Animal Spirits, and by consequence, in the faculty of Imagining.

I know that there are some Persons, who do not believe that the Air mingles it self with the Blood, in the Lungs and Heart, because by their Eyes they cannot discover, in the branches of the Wind-pipe and those of the Venous Artery, the passages whereby the Air is communicated. But we must not confine the Action of the Mind to that of the Senses, it can penetrate what is impenetrable by them, and apply it self to such things which they cannot. 'Tis certain, that some parts of the Blood continually pass from the branches of the Venous Artery, into those of the Wind-pipe, as the smell and moistness of the breath sufficiently proves, and yet the passages of this com∣munication are imperceptible; why, therefore, can∣not the subtile parts of the Air pass from the branches of the Wind-pipe into the Venous Artery, altho' the passages of this communication are not so visible. In short, more humours are evacuated by transpira∣tion, from the imperceptible Pores of the Arteries and

Skin, than by any other passages of the Body; and even the Pores of the most solid Metals are not so small, but that there are Bodies in Nature small enough to find a free passage, for otherwise these Pores would be clos'd up. It is true, that the Gross, and branchy parts of the Air, cannot pass through the ordinary Pores of Bodies; and that even Water, altho' very gross, can glide through those passages, where this Air is sometime forced to stop. But we are not speaking here of those gross and branchy parts of the Air; they are, it seems, unuseful enough for fermentation, 'tis only of the smallest parts, such as are swift and sharp, that we speak of, and which have none, or very small branches, to stop them, be∣cause they are the most proper for the fermentation of the Blood.

I might, nevertheless, affirm, upon the Relation of Silvius, that even the grossest part of the Air pass from the Wind-pipe into the Heart, since he assures us, that he hath seen it pass thither by the help of M. de Swamerdam; for it is more reasonable to believe a Man, who says he has seen it, than a thousand others, who only speak of it by chance. It is then certain, that the most subtile parts of the Air, which we breath, enters into our Heart, and with the Blood and Chyle, maintains there that fire which gives Life and Motion to our Bodies; and that, according to their different Qualities, they produce great changes in the fermentation of the Blood, and in the Animal Spirits.

The truth of this is every day made evident, by the divers Humours, and different Characters of Per∣sons dispositions that are of different Countries. For Ex∣ample, the Gascons have a more lively Imagination than the Normans; those of Roan, Diep, and Picardy, differ very much among themselves, and that much more from the Lower Normans, altho' they be very near together: But if we consider Men, whose Coun∣tries are at a greater distance, we shall meet with dif∣ferences still more strange, as an Italian, and German, or a Dutchman. In fine, there has in all times been

some places that have been renowned for the Wisdom of their Inhabitants, as Teman and Athens; and others for their Stupidity, as Thebes, Abdera, and some others.

Athenis tenue coelum, ex quo acutiores etiam putantur Attici, crassum Thebis. Cic. de fato.

Abderitanae pectora plebis habes. Mart.

Boeotum in crasso jurares aere natum. Hor.

Notes

• Nunquid non ultra est sapientia in Teman? Jer. c. 49. v. 7.