It is not simply a series of instructions which we make here, it is an appeal to all who interest themselves in the cause of science and of their country. We will point out to them the means of enriching this great national establishment, which, open to public curiosity and study, can only be rendered perfect by the aid of many hands. It cannot itself support travellers except upon a few limited points, and even there, such is the inexhaustible fecundity of nature, much remains to be done. As for amateurs, who can give but few moments to the study of Natural History, who have not hitherto occupied themselves with it, but who have, notwithstanding the desire to render their sojourn in certain points little explored, profitable to our object, we have thought that instead of collecting a great number of objects, they would do well to limit themselves to such as are signalized as curious and indicated in the list of our _desirata_. They could thus economise time, and employ it more usefully, not only in collecting the objects which we recommend but also in bestowing upon them that care which would insure their preservation. These instructions are devided naturally into three chapters, corresponding to the three kingdoms of nature; each part has been prepared by such of the professors as it especially concerns. The instructions will make known: 1º The manner of collecting and preparing objects of Natural History. 2º The choice and form of the notes which should accompany them. 3º An indication of those which are more particulary wished for. It remains for us before proceeding to the special details of this memoir, to give general instructions upon the packing of objects of Nat. His. and upon the modes proper to be employed to prevent any damage to them during their voyage. As soon as the objects prepared as before directed, have been placed in case these cases must be closed in the best possible manner and covered with pitch or tar on their whole surface; so that neither air nor moisture can penetrate. After this, they must be envelopped in oil cloth, and then put on board ship in such place as will be likely not to be disturbed till their arrival, and as far from the heat and vermin as possible. Glass bottles should be packed in wooden boxes well filled with tow and sea-weed; and arranged so that they will run no risk of breaking; objects which may be spoiled by liquids in the glass bottles, should they happen to break, should not be placed with them. When a package has been sent, information should be given directly with the statement of the number and weight of the boxes, of the ship by which they are sent, the time of sailing, and the port to which they are bound. These statements should be made in time so that boxes may be sealed at the Custom House and not be opened until they arrive at Paris.