From later botanical researches, we learn, that the bountiful Creator has enriched the earth with about 20,000 different species of vegetables. The following statement of the progress of botanical knowledge has recently been given to the public. Messrs. Humboldt and Boupland, the celebrated travellers, have collected in their five years’ travels through South America, 3,800 species of plants, of which upwards of 3,000 were new, and absolutely unknown before to the botanists of Europe. We are at present acquainted altogether with 44,000 species of plants; while the whole number mentioned by the Greeks, Romans, and Arabians, does not exceed 1,400. It is worth remarking, that the vegetable productions of the new world seem to have been in an inverse ratio, both in point of number and luxuriance, to those of the animal kingdom. In North America, for instance, the number of lofty trees is far greater than in Europe. In the former country, there are found 137 species of trees, whose trunks exceed the height of 30 feet; while in Europe there are scarcely 45 species. But it is singular there are no firs to be found on any part of the mountains of South America, between the tropics, though they are very abundant in North America. The reason why Magnolias, and other equinoxial plants, appear so far north in America, is, that as far as lat. 48 deg. the summers are 9 degrees (of Fahrenheit) hotter than in the corresponding European latitudes. The winters, however, are more than proportionably colder. At Philadelphia the summer is as hot as at Rome; while the winter corresponds with that of Vienna. At Quebec, the summer is warmer than at Paris; the winter colder than at St. Petersburgh. Beyond Lake Superior, and at Hudson’s Bay, it is said that the earth is perpetually frozen at the depth of three feet from the surface, which prevents the inhabitants from digging wells. The same thing happens in Siberia, on the banks of the Lena; while in South America there are cities at a greater height than the highest summit of the Pyrenees, and houses more elevated than the Peak of Teneriffe, the region, in Europe, of perpetual congelation. To this we may add, that Linnæus, the celebrated botanist, divided all plants into classes, the classes into orders, the orders into genera, and the genera into species: and the species, we are told, amount perhaps to 40,000, or 50,000, or more!