He made the first elaborate reports of popular scientific lectures by Louis Agassiz and other authorities.
The last of these was that of Louis Agassiz (1807-1873), who, whilst surveying all previous classifications, propounded a scheme of his own (Essay on Classification, 1859), in which, as well as in the criticisms he applies to other systems, the leading notion is that sub-kingdoms, classes, orders and families have a real existence, and that it is possible to ascertain and distinguish characters which are of class value, others which are cnly of ordinal value, and so on; so that the classes of one sub-kingdom should on paper, and in nature actually do, correspond in relative value to those of another sub-kingdom, and the orders of any one class similarly should be so taken as to be of equal value with those of another class, and have been actually so created.
The visit of Professor Louis Agassiz to the Amazon in 1865 resulted in a list of 1143 species, but it is believed that no less than 1800 to 2000 species are to be found in that great river and its tributaries.
Bates (1848-1859), Hermann Burmeister (1850-1852), Louis Agassiz (1865-1866), Charles Frederick Hartt (1865-1866, 1872 and 1875-1878) and Karl von den Steinen (1884-1885 and 1887-1888).
His attention was directed to the question of the flow of glaciers in 1840 when he met Louis Agassiz at the Glasgow meeting of the British Association, and in subsequent years he made several visits to Switzerland and also to Norway for the purpose of obtaining accurate data.
Dana and Louis Agassiz had already arrived at the same conclusion.