286 Progress in Science, [April, 



Zirkel shows that the small rounded granules of serpentine so widely 

 disseminated through certain crystalline limestones have in many cases resulted 

 from the alteration of olivine, and it seems likely that his researches in this 

 direction may eventually shed some light on the origin of the so-called 

 eozoonal structure exhibited by many serpentinous limestones. 



We are glad to learn that one of our English chemists — Mr. John Arthur 

 Phillips — is busying himself with the chemical and microscopic study of some 

 of our British rocks and minerals.* Many of the old ore-bearing rocks of 

 Cornwall have received Mr. Phillips's attention ; but so far as they are rock- 

 masses and not minerals, any notice of them scarcely falls within the scope of 

 this chronicle. One of the subjects of our author's study is, however, a 

 felspathic mineral which is quarried at the glass mine, near Roche, and ex- 

 ported to the potteries. It is a yellowish white crystalline mineral, enclosed 

 in a schorlaceous granite, and traversed by veins of milky quartz. On analysis 

 it was found to be an orthoclase containing 10*37 P er cent °f potash, and 2-4 

 of soda, with about i*6 of lime; whilst its monoclinic form was determined 

 by Professor Miller's crystallographic measurements. Analyses are also 

 published of the beautiful serpentine of the Lizard — a substance which may 

 be regarded with equal propriety as a mineral or as a rock. The specimen 

 analysed by Phillips presented a dark green colour, thickly spotted with red, 

 and exhibited under the microscope a crypto-crystalline base, with spots of 

 oxide of iron, accompanied by indistinct crystals of a green or yellowish brown 

 colour, which it is suggested may be pseudomorphs after pyroxene. 



An interesting essay on the relation subsisting between chemistry and 

 mineralogy has been published by Professor Rammelsberg.f At once a dis- 

 tinguished chemist and an excellent crystallographer himself, he maintains 

 that every mineralogist should be equally familiar with both these sciences, 

 and points out the mischief which must necessarily result from any attempt 

 at divorcing two branches of science so closely cognate as chemistry and 

 mineralogy proper. Indeed, our author is bold enough to repeat the question 

 which had previously been mooted, "Might it be allowed to call chemistry and 

 mineralogy one science ? " Believing that it is the duty of all who are 

 interested in mineralogy to keep pace with the progress of modern chemistry, 

 he denounces the persistence with which many mineralogists cling to the 

 old-fashioned atomic weights and rational formulas. In these respects 

 Rammelsberg's views are directly opposed to those of Von Kobell, or at least 

 to those which he held a year or two ago. \ We believe, however, that any- 

 one who follows up mineralogical literature cannot fail to observe that the 

 conservatism which has long been imputed to the mineralogist is gradually 

 yielding, and that at any rate most of the younger men cannot be accused of 

 lagging behind their age. 



At the request of Professor Weisbach of Freiberg, Herr Frenzel has analysed 

 the two minerals which were recognised as distinct many years ago .by 

 Breithaupt under the names of Plumbosiib and Embrithite. || These new 

 analyses show that the two minerals in question have identically the same 

 chemical composition, both being represented by the formula ioPbS + 3SbS 3 . 

 It is probable that they should be consolidated into one species; and if this be 

 done, our author suggests that of the two names in vogue " Plumbostib " 

 should fall to the ground. 



O'Reileyite is the name which Mr. D. Waldie proposes§ for a new Burmese 

 mineral obtained from the late Mr. O'Reiley, of Martaban. It contains 

 arsenic, iron, and copper, approximately in the proportions of two equivalents 

 of As, six of Fe, and one of Cu. 



Mr. J. S. Adam has analysed some specimens of the rare mineral Gahnite, 

 or zinc-spinel, found by Professor Brush, at Mine Hill, Franklin Furnace, New 



* Philosophical Magazine, Feb., 1871, p. 87. 

 4 Chemical News, Feb. 10, 1871, p. 64. 

 t See Quart. Journ. Science, July, 1868, p. 416. 

 II Journ. fiir prakt. Chemie, No. 18, 1870, p. 360. 

 § Chemical News, Jan. 6, 1871, p. 4. 



