We have the hope that, with the aid of the Daguerreotype and physionotype, the american naturalists will enrich anthropology with results of great interest. By photographic portraits, such as those presented to the Academy by M. Thiesson; by mouldings to be added to the fine collection made by M. Dumoutier, now in the museum; by colored drawnings, by descriptions and measures, they would transmit us information of extreme precision, true scientific elements, to which the committee would attach the greatest importance. We think it our duty to direct the researches of the american naturalists, not only to the different varieties of the American race, but also to the half-breeds, yet so little known, of both, and, also, to the offspring of the crossing of the first with the Caucasian race. We request them, as soon as they shall have determined exactly the physical characteristics of these difficult varieties, to neglect no information that may enlighten us as to their intellectual capacity. We would, likewise, entreat these gentlemen to specify exactly and express by colored drawnings done with care, the different states of the hues of the American races and half-breeds, from the moment of their birth up to the period that they arrive at the normal color of their kind. We would desire them, besides, to collect, of these same races, their half-breeds, and the white race, more minute particulars than as yet obtained, on the duration and difficult phases and epoch of puberty. _Chemistry and agriculture._--These are the principal forms that allow the use of Caoutchouc without dissolving it and without altering the heat. 1º Straight tubes; elbowed tubes; tubes in T of different thickness and diameter; 2º Full cylinders, to be cut in France as wanted; 3º Rectangular plates, cut in France; 4º Caps to cork bottles and flasks. It would be desirable to examine, in an economical point of view, the question of the preparation of preserved sugar, transportable to France, and giving, by a simple preparation, elastic caoutchouc. _Dye woods and other vegetable products_.--Details on the working of dye woods, their qualities, uses, marks, would be interesting for technology. It would not be less useful to send samples, branches, leaves and flowers of the usual plants, whose products are or may be applied to tanning; the extraction of oils, etc. _Remains of animals._--It is known that domestic animals, transported by Europeans to America, have multiplied and spread. It results from this that products which in Europe and particulary in France, are needed by agriculture and the different acts, are in great part lost in Brazil and several countries of south America. To send them to France or our colonies should be prepared: 1º For manure, blood coagulated by heat or lime, and dried; 2º For nourishment or manure, dried flesh;