Terra Firma and the Mouths of the Oronooko.

The vessels which go to Martinique and Cayenne, having, as we have already said, frequent communications with Terra Firma and the mouths of the Oronooko, might easily procure us the plants we chiefly desire from these regions, by asking for them under the names by which they are known in the country.

From Cumana, branches in flower, and ripe fruits of the cuspa, which we call jesuits' bark (cascarilla), and which we must not confound with the cuspara of the missions of Caroni. The cuspara furnishes the quinquina (jesuits' bark) of Spanish Guyana, called in Europe, cortex angusturæ.

The vessels visiting the ports of Guaira and Porto Cabello might bring some branches in flower, and some fruits of the cow-tree (arbol de la vacca), which resembles the chrysophyllum in the family of sapoteæ. This tree grows near Barbula, between Porto Cabello and Nueva Valencia. It will be highly important to bring also several well-corked bottles of this vegetable milk, which gives nourishment to the inhabitants.

Santo Thomas de Angostura, and the Mouths of the Oronooko.

The leaves, the flowers, the fruit, and the farina of

the trunk of the moriche palm, celebrated amongst the Guaraunos Indians. A branch with the flowers, as well as the fruits, of the cuspara or quinquina of Caroni (cortex angusturæ.) Branches in flower and fruits of the tree which affords the almonds of the Rio Negro, and which bears the name of almendron or juvia (bertholetia excelsa.) The branches, the flowers, and the fruits of the chickichik palm, of which they make cordage in the missions of Oronooko.

New Holland.

Cucalyptus and casuarina (Fam. myrti et coniferæ.)

Besides the collections of living vegetables, plants preserved in herbals, and products of the vegetable kingdom, the Museum possesses an assortment of tools, machines, utensils, and substances, employed in gardening, in agriculture, and in rural economy. This assortment, already very rich in the implements of the different nations of Europe, still requires the tools, &c. of other parts of the world. They would be received with pleasure and gratitude.

MINERALOGY AND GEOLOGY.

MINERALS are found either in regular and geometrical forms, which bear the name of crystals, or in masses more or less irregular. Amongst the crystals, there are some so situated, that we can, without injury, separate them from their support or the substance which surrounds them. Others compose groupes projecting beyond their support, and others appear buried in cavities in the interior. We must procure, as frequently as possible, the specimens in these three states. As regards the crystals inserted within the surrounding substance, we detach parts of this substance with them, at least from three to four inches large in every sense, so that we may observe the different minerals which accompany the crystals. We also detach portions of the masses composed of needles, fibres, of the granulous or compact, taking care to choose them in a state of freshness, and free from alteration, which is most obvious in those situated near the surface.

In collecting fragments or specimens of rocks, minerals, volcanic products, or fossile organised bodies, it is most essential to note their stratification well, that is to say, the nature of the place in which they are found, and their relative position

with the minerals which environ them. In detaching specimens from these mines, they must take care to leave round the principal metal, either portions of the other metals which are associated with it, or of the stony substances which often accompany it, especially those which are crystallised.

If they find earths which contain the remains of organised beings, such as the bones of animals, shells, impressions of fish and vegetables, they should collect, with care, specimens of these different bodies, having them enveloped in a portion of the earth or stone in which they were fixed.

In case the traveller should find any traces of volcanic origin, he should procure specimens of the different substances thrown up by explosions, some of which are in a state of stone like basalt, others similar to glass like obsidian, others in a state of scoriæ. For those that are in prisms, care should be taken to note the form of these prisms, and the extent they occupy in the soil.

A ticket should be fixed to each specimen indicating the name of the country where it was found, the spot from which it was taken, the distance of this place from, and its situation with respect to, any known town in its neighbourhood; as nearly as possible, the natural and general aspect of the soil, and its elevation above the level of the sea.

Wherever warm or mineral waters are found, care should be taken to fill phials with them, which should be well corked and luted.

Since we have abandoned systems to confine ourselves to the observation of facts, and to compare these observations; since we have renounced the attempts to guess the origin of things, in order to ascertain their actual state; geology, which formerly belonged to the domain of imagination, has followed the course of the positive sciences. This regular method has not only extended our knowledge of the construction of the earth, but has even produced results useful to the arts. We are far however from knowing the different countries of the globe as we know Europe, and the facts necessary for fixing our ideas can only be collected by travellers, who are well informed on, and devoted to, this kind of study. But it is very easy for those who visit distant countries, especially beyond the tropics, to procure us important notices, and to send us productions, the examination of which can alone enlighten and furnish us with ideas on the nature of the soil in different countries, and consequently the general disposition of the minerals which cover the surface of the globe. On all coasts, in all the islands, which a vessel harbours, those who go on shore can without much difficulty procure objects, which, not possessing any value in themselves, may become instructive and interesting from the notes by which they are accompanied. They first collect, on the borders of rocky torrents, fragments which