This is easily attained, by designating by a common number, letter, or any sign whatever, one particular formation or stratum, and by marking with the same sign all the petrifactions which are evidently found together.
The labels designating the place or the geological situation, may be placed in the papers which envelope the specimens, or a number, referring to an explanatory catalogue, may be attached to each specimen.
As far as possible, it is necessary to stick the labels or numbers to the pieces, by pasting; and the surest way is, to write upon the piece itself, 1st, the place where it is found; 2d, the number by which it is indicated in the historical notes above requested.
If there is not time to make out as many numbers or labels as there are pieces, it will be sufficient to unite in one box or packet all the petrifactions of one particular stratum, and to designate them by a general label.
It is necessary to pack the shells and other fragile pieces in separate boxes, and to wrap each piece in a separate paper.
M. Brongniart cannot allow himself to prefer such requests, except under the express condition, that a memorandum of all the expenses which the transportation and packing of the specimens may create shall accompany the letter of advice.
The objects destined for him may be sent by the common modes of conveyance, with a letter of advice, to the following address:
Mr. A. Brongniart, Member of the Royal Academy of Sciences, Engineer of Mines, etc. Rue Saint-Dominique, Faubourg Saint-Germain, No. 71, Paris.