Leaves of paper containing plants, should be well pressed together in packets and placed between two sheets of plain paper, before being put in boxes.
In packing up, several samples may be placed between each leaf of paper, and the number of leaves placed between be lessened, if necessary; the packets should always be well pressed together. Any kind of paper is good for packing; bananas or any large-leafed plant can replace it; it is only necessary that the plants should be arranged with care, so as to give an equal thickness to the packets in all their parts.
If there is time the specimens should be preserved by plunging the dry plant in an alcoholic solution of corrosive sublimate (15 to 20 grammes for a litre of alcohol at 36°), or to rub it with a pencil, then to dry it in a leaf of paper, which requires but a few instants. With this precaution, all the specimens sent may be preserved; and for not making use of it, several parcels of plants have arrived damaged by insects.
If the plants are fumigated with sulphur, they will be preserved from insects for a long time.
Among those sent, there will be many we have received before; but they will not be useless.
Plants preserved in herbals, which we already possess, will be employed in forming special herbals for different countries, very useful for the study of botanical geography and to facilitate the researches of travellers, either by making exchanges, with foreign museums, or to enrich the principal museum of the departments.
Besides, there are always objects that corrupt by time, which it is useful to renew.
Collections of plants, from whatever country they come, have always a certain number of plants which the museum does not possess, or offers them in a different state from those we possess and so are always interesting, when well made; but there are countries little known, from which we desire to receive all that can be collected.
The North-America: the Floridas and southern parts of Louisiana, Arkanzas and Texas, a great part of Mexico, particulary the northen part, as well as California, the southern part of Mexico, and the countries comprehended between that state and the isthmus of Panama; the great iles of the Antilles, Haïti, Cuba and Jamaïca, though formerly explored, are now scarcely represented in our herbals.
Botany is already cultivated with success in many countries. Travellers can, sometimes, find herbals already collected; it would be useful to procure them, especially if they have but a short time to stay or even a single season, after assuring themselves that these herbals are made with care. This would be important, especially in countries where the flora has been treated by some resident botanist, and the kinds and species proper to these local floras should, if possible, be obtained.