Letters of Mr. Brongniart, with remarks. 219 



ticular thanks for your kindness in sending it to me. I have 

 not only myself derived from it both pleasure and instruc- 

 tion, but I have put in the power of various persons to en^' 

 joy it also, and they as well as myself find it very well exe- 

 cuted and consequently very interesting. I was gratified to 

 observe that you had been so kind as to insert the notice 

 upon the manner of collecting petrifications ; a notice 

 which I had not myself published except for the promotion 

 of my own views ; still I tender you my acknowledgments. 



" But I reserve for the end of this letter, the object that 

 has interested me most, and that which has been with me a 

 subject of instruction and of very varied reflections — name- 

 ly, the rocks and petrifications, which you have had the 

 kindness to send me and which I received in^ October last. 



" I have already made an incipient study of them, and I 

 intend to return to it when I shall be able to combine all the 

 means adapted to determine exactly or rather more precise- 

 ly these fossil organized bodies. I shall confine myself then 

 for the present, to the communication of some of the reflec- 

 tions, which these rocks have excited, and of some of the 

 determinations which I have made respecting them ; these 

 determinations are made in accordance with the classifica- 

 tion of mixed rocks which I published in 1813. 



" The serpentine of New-Haven, of which you have sent 

 me so beautiful a specimen, constitutes one of the ornaments 

 of my cabinet and is referred with great precision to my spe- 

 cies, ophicalce veinee*, (viz. veined serpentine limestone.) 



" The rocks which accompany the Anthracites of Wilkes- 

 barre and of Rhode-Island are, according to my classifica- 

 tion, the -fPhyllades pailletees ; one of them contains the 

 impression of a leaf of fern, whose species appears to me a 

 little different from all those of Europe which I possess. 



" I shall be very desirous that circumstances may permit 

 you to enrich me still further, with specimens bearing the 

 impressions of vegetables, and of all other fossil organized 

 bodies, which are found in your coal formations, or in those 

 of anthracite, and finally in all your bituminous formations. 



* This remark was quoted in Vol. 2, p. 165, under the head of AmeriGan 

 Vtrd Antique Marble. 



t The Phyllades of Mr. Brongniart are schists with an argillaceous basis, 

 cCritaining mica, quarlx, feldspar, smphibole, marl, &c. 



