Wherever mineral waters shall be found care will be taken to fill a bottle, to cork and cement it closely.
Since those systems have been abandoned which restrained the observation of facts and comparison of those observations; since guessing of the origin of things has been renounced for studying their actual state; geology has advanced like other correct sciences. This advance has not only extended our acquaintance on the formation of the globe, but has also produced useful results for the arts. Notwithstanding we are far from knowing the various countries of the earth as we know Europe.
It is easy for those who visit these distant countries, above all the tropics, to procure us important ideas, and to send us productions, the examination of which can alone enlighten and furnish us informations on the nature of the soil in those countries and the general arrangement of the rocks which constitute the outside of the globe.
On all coasts and islands where vessels stop, travellers can land and procure objects with little trouble, which having little value in themselves, become instructive and interesting by the simple annotations which accompany them.
They can pick up on the borders of torrents pebbles which indicate the nature of the rochs from which they proceed. They will choose the largest and note their size, and also break some pieces,—also the small pebbles, having care to choose those of different appearances.
Wherever a rock is seen to rise, should it be in the water or land, it should be observed if it is all of the same substance or homogeneous or composed, or formed of different beds. In the first case a fragment must be detached, in the second case, they will observe the relative position of the beds, their inclination and thickness; and take a sample of each of the beds, and put the same mark on all the pieces coming from the same mountain, and a number on each to indicate the order of their position or reciprocal situation. If the person who procures these samples could make a simple sketch, to show the form of the mountain, the thickness and inclination of its layers, he would render an essential service.
In case the rock is an isolated one, it is useful to examine and sketch on both sides to be more certain of the inclinations of the beds.
It would be well to gather some sand from the bottoms of rivers; above all those which wash metallic dusts; but this sand must be taken as far from the mouth of the river as possible.
In some countries are found isolated masses to which the people attribute a singular origin; pieces must be taken; perhaps they are aerolithes; other may be transported by the revolutions of the globe.
In gathering fragments of rocks, mines, volcanic products and organised fossil bodies, the most essential thing is to mark well their latitude, that is to say the nature of the earth where they are found and their relative position to the substances which encircle them.