88 Professor Vanuxem on the MarmoUte o/"Mr. NuttuU. 



dition depend upon the arbitrary expression of the probabi- 

 lity of an error. But when we set out with demonstrating 

 the most advantageous solution from the nature of the equa- 

 tions of conditions, the whole theory follows naturally, and 

 is placed on its proper foundation. 



For better illustrating the principles of this important spe- 

 culation, I shall resume the subject on a future occasion, and 

 offer some further remarks upon it. 



February 3, 1825. James Ivory. 



XIV. On the Marmolite of Mr. Nuttall. By Lardner 

 Vanuxem*. 



THE description and analysis of this mineral was published 

 by Mr. Thomas Nuttall, in vol. iv. No. 1. of the American 

 Journal of Science and Arts. 



Having last summer visited with Professor Keating the 

 Hoboken locality of serpentine f , I was enabled to make a 

 number of observations ; the communication of which I hope 

 will not be uninteresting, or considered unimportant by the 

 Academy. 



For some years past considei'able doubt has prevailed 

 among many of the best mineralogists with respect to the 

 propriety of retaining serpentine as a mineral species, having 

 few or none of those external characters required to substan- 

 tiate its claim to such a rank. By some, serpentine has been 

 considered as a rock, whose substance appeared to be the re- 

 sult rather of a mixture of different minerals, or the elements 

 of different minerals, melted and deposited in a confused state, 

 than an homogeneous substance or simple mineral whose 

 aggregate has been effected by the power of chemical affinity. 

 That it is not generally regarded to be a mineral, siii generis, 



* From Jour, of the Acad, of Nat. Sciences of Philadelphia, vol. iii. p. 129. 



t The author of the paper on the marmolite considers the serpentine of 

 Hoboken, (N. J.) to " appertain rather to the transition than the primitive . 

 range;" on what ground I know not, further than the circumstance of a 

 part of it being in fragments, and these fragments connected together so as 

 to form a breccia: but this fact is susceptible of an explanation by which 

 the primordial character of the mass remains in all its integrity. Serpen- 

 tine, like many other rocks, is split or cracked in various directions; in 

 8ome parts of the serpentine of Hoboken, the cracks or fissures are very 

 numerous, of course the fragments are small. These fissures in many in- 

 stances are filled with carbonate of lime, so that the fragments form one 

 solid mass. Now this fact is analogous to those parts of a rock, one of the 

 primitive class for example, which are traversed in different directions by 

 veins in series ; and no one ever supposed that the intervening masses lost 

 their primitive character from the presence of such veins. 



it 



