272 Dr. Thomson*s Answer to the Revietvofthe [Apr it, 



ters. We find the same chapter, in the same words, in the 

 former edition, but with a reference to Mr. Jameson, which is 

 now suppressed. The only observable alteration, indeed, in his 

 present article on Mineralogy, is the erasure of Prof. Jameson'?? 

 name wherever it formerly occurred." — (Review, p. 166.) 



The arrangement of minerals which I have adopted is that of 

 Werner, with a few slight alterations to fit it better for a chemi- 

 cal work. If it be a chaos, then the same term may be applied 

 to every system of mineralogy which has hitherto appeared. 

 How far the Reviewer's statement, that the Mineralogy in my 

 sixth edition is just a reprint of that in the fifth, the reader will 

 be enabled to judge when I inform him that it contains no fewer 

 than 38 new species, the names of which I shall here subjoin for 

 the Reviewer's satisfaction : 



Turquoise, Bucholzite, 



Peliom, Papercoal, 



Colophonite, Eucairite, 



Helvine, Tennantite, 



Eudyalite, Seleniuret of copper, 



Allophanite, Bismuthic carbonate of copper, 



Basalt jasper, Titaneous iron ore, 



Spherulite, Sulpho-arseniate of iron, 



Karpholite, Skoroclite, 



Mesolite, Knebelite, 



Skolezite, Carbo-sihcate of manganese, 



Petalite, Glance nickel, 



Gieseckite, Wodan pyrites, 



Ambligonite, Arseniate of nickel, 



Caranthine, Antimonial sulphuret of lead, 



Calamite, Arsenio-sulphuret of lead, 



Baikahte, Antimonial arseniate of lead, 



Fassaite, Tungstate of lead, 



PolyhaUte, Aluminate of lead. 



Besides these new species, which constitute no trifling addi- 

 tion, I have changed the position of a considerable number of 

 species, rectified the description of more than two-thirds of the 

 whole, and added many new analyses, all indeed that had come 

 to my knowledge. 1 conceive, therefore, that the attention 

 which I paid to this part of the work, and the improvements 

 introduced into it, are much more considerable than could have 

 been anticipated. Instead of censure, therefore, I was entitled 

 to no small degree of praise. 



With respect to the system of Mohs, which has been adopted 

 by Jameson in his last edition, I must confess myself an incom- 

 petent judge, because I do not understand it. I have perused 

 Alohs' little treatise on the Characters of the Classes, Orders, 

 Genera, and Species, a copy of which the author did me the 

 honour to present to me. 1 have likewise read the account of 



