Mineralogy — Crystallography. 1 81 



24. A similar variety of the same from Freiberg. 

 (See the Annates des Mines, t. xiii. p. 887.) 



30. Torrelite. — Under this name in honour of Dr. Torrey, the analysis 

 of a mineral by Professor Renwick. has been published, which is found 

 in Sussex county, New Jersey, and supposed to be new. It yielded 



Silica, . . 32.60 



Peroxide of cerium, . 12.32 



Protoxide of iron, . 21.00 



Alumina, . . 3.68 



Lime, . . 24.08 



Water, . . 3.50 



Loss, • • 2.82 



100.00 



31. Metallic Titanium — Metallic titanium, first discovered by Dr. Wol- 

 laston in the iron slags from Mcrthyr Tydvil, has lately been found by 

 Dr. Walchner in similar slags from the high furnace of Kanderea in 

 Baden, and appear from the description given to be exactly similar to 

 those which have been found in this country. (Schweigger's Journal, 

 xi. p. 80.) 



CRYSTALLOGRAPHY. 



32. The Edinburgh Review and Mr. W. Phillips. — In an able article in 

 the Edinburgh Review on Mineralogical Systems,* well worthy of being 

 perused by those who are bigoted to their own views of that science, 

 the acute author has stated it as a fact, which must " affect the degree 

 of confidence which we can place in crystallographic indications," that, 

 according to Mr. W. Phillips, the differences in the angles of cleavage 

 planes, amount even to fifty minutes of a degree. In a sharp note in the 

 Annals of Philosophy, No. xl. p. 285, Mr. Phillips has shown that the 

 Reviewer had mistaken his meaning, in using the word cleavage, as he 

 meant the natural planes of the crystals. 



This slight oversight being admitted, justice compels us to vindicate the 

 Reviewer (of whom we have no knowledge) from the charge of ignorance 

 too strongly brought against him ; and to state with confidence, that the 

 Reviewer's argument is not in the slightest degree affected by this over- 

 sight. 



Mr. Phillips distinctly states, that " the measurements of the Crys- 

 talline forms, and especially of the secondary planes (given in his own 



* We trust that the author of this article will reconsider the opinion which he 

 has stated on the system of Professor Mohs. Had he studied Mr. Molls' own 

 work, which has been published in German, and which will soon appear in Eng- 

 lish, he never could have expressed such an opinion. It is hard, that the labours 

 of such an eminent mineralogist should be judged of from the erroneous accounts 

 of them that have been given by persons who have not even studied his writings. 



