Art. XIII. Notice of M. Brongniart on Organized Remains.
Art. XIII. Notice of M. Brongniart on Organized Remains.
This distinguished mineralogist, so advantageously known by his excellent work on mineralogy—his researches in company with Cuvier, into the subterranean geography of the environs of Paris, and his superintendence of the great porcelain manufactory at Sevres, is attempting to form an extensive collection of organized remains.
Through Professor Cleaveland, we have received from him the following
NOTICE
Concerning the method of collecting, labelling, and transmitting specimens of fossil organized bodies, and of the accompanying rocks, solicited by M. Brongniart.
The study of fossil organized bodies appears to be of the utmost importance in determining the relations of different formations, one of the principal objects of geology.
In order more effectually to appreciate the value of this method of investigation, it is necessary to multiply observations—to endeavour to render them exact and precise—and especially to make them upon a general plan.
M. Brongniart has been long occupied in such researches. The essay published by M. Cuvier and him, upon the geology of the environs of Paris, has afforded an example of their use.
He has laboured since this period to apply this method to other formations, which contain the relics of organized bodies; but he stands in need of much assistance, and he presumes to ask it, not only of naturalists, but even of all persons interested in the sciences. By means of the following instructions, he endeavours to avail himself of the kindness of persons the least conversant in the discrimination of fossils.
1. To collect all the fossil organized bodies which can be obtained; especially the distinguishable impressions and remains of vegetables from coal countries, and beds of wood, coal, and others. The shells, crustaceæ, madrepores, fishes, &c. It is not necessary that these bodies should be either large or entire, but they must be sufficiently characterized to be capable of being recognized.
It is useless to transmit large unmeaning pieces, which are recommended only by their size—such as large ammonites—large madrepores—large pieces of petrified wood—fragments of the one, or small individuals of the other, are often sufficient. We may avoid also collecting the inner moulds ("des moules interieurs") of shells, because they are almost invariably incapable of being recognized.
2. Petrifactions, isolated and detached from their rock, are the most convenient in the determination of species; but when they cannot be separated from the rock, we need not hesitate to send them engaged; it is sufficient if a portion large enough for discrimination is visible.
Among shells, those are preferable which have the mouth or hinge in view; among madrepores, those on whose surface the figures (les étoiles) are distinguishable; among vegetables, those whose leaves are distinctly expanded, (expalmées.)
3. Upon the objects transmitted it is desirable to have, at least in part, the following notices:
1. The exact place from which the object comes: this is the most important circumstance, and the easiest to obtain.
2. The kind of formation in which it is found, and a specimen of the stratum, or at least of the rock, which contained it. It is desirable that this rock exhibit remains of petrifactions similar to those found in the stratum from which it has been drawn.
3. The nature of the formation of which this stratum or rock composes a part, and specimens of as many of the superior and inferior strata as can be obtained, designating the order of superposition of the strata.
4. It is important to designate, by the same mark, all the petrifactions unquestionably found in the same stratum, or at least in the same formation. The specimens ought to be almost square—about three inches or more on a side, and one and a half thick.
5. It is equally important not to mix petrifactions found in different formations, or in different strata of the same formation; or if they are packed together, to distinguish them by numbers, marks, or labels.
When the preceding notices cannot be obtained, the first will suffice.
In order to collect the petrifactions, and to render them useful, it is not necessary to know them, nor to be perplexed to find them out; nor to be afraid of sending objects already known or of little note. A part of the preceding indications, connected with the most common petrifactions, will always render them useful. The important point then is, not to mix those which are found separate, nor to separate those which are found associated in the same stratum.
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.