If the shape of the land here described by Mr Marsden has been produced by means of water, it must be by water moving from a higher to a lower place; and, in that respect, it is the same operation which every where prevails, in producing similar effects, although it is not every where that this effect comes to be the object of our notice.  It is therefore so necessary to illustrate, in giving a diversity of cases.  But it is not every case that can be understood as belonging to this rule; for, though the shape of every part has been modified by the operation of this cause, it is not every where that this relation of cause and effect is immediately perceived.  There must be a certain regularity in the parts to be described, and a certain conformity wish those in which we have no doubt, or in which we certainly acknowledge the efficacy of the cause.

In America, this system of swamps and savannas are to be found upon a large scale; but for this very reason, they are not so remarkable to men.  Man only sees a system of things, so far as that system is more immediately within the reach of his perception; for, without having prepared media, by which he may compare things that are distant either in their nature or their place, How could he judge those things to be connected in a system?  It is in this manner that, seeing only the small part of an extended system of things, he sees no system in it, and, consequently he cannot give any scientifical description of the subject.

There is another case in which men of science, or systematising men, are apt to fall into delusion:  it is not from any deficiency of seeing effects, and knowing general causes; it is from the misapplication of known causes to effects which are perceived.  We have a remarkable example of this in the view which M. de Bouguer has taken of a singular appearance which he met with, perhaps more interesting to the present Theory than almost any other of which we know. (Voyage au Perou, page 89.)

“Une particularite qui a attire souvent mon attention dans toutes ces contrees, c’est que toutes les montagnes aupres desquelles je passois, et qui sont au pied et au dehors de la grande Cordeliere, me paroissoient avoir eu une origine toute differente de celles que j’avois vues auparavant.  Les lits de differentes terres et le plus souvent de rochers dont elles etoient formees, n’etoient pas inclines de divers cotes, comme dans les autres:  ils etoient parfaitement horizontaux, et je les voyois quelquefois se repandre fort loin dans les differentes montagnes.  La plupart de celle-ci ont deux ou trois cent toises de hauteur, et elles sont presque toutes inaccessibles; elles sont souvent escarpees comme des murailles:  c’est ce qui permet de mieux voir leurs lits horizontaux dont elles presentent l’extremite.  Le spectacle qu’elles fournissent n’est pas riant, mais il est rare et singulier.  Lorsque le hazard a voulu que quelqu’une fut ronde, et qu’elle se trouvat absolument