Oct. 13, 1887] 



NATURE 



575 



The author concludes with a brief sketch of the great divisions 

 of the indigenous crenitic roclts recognized by him, from the most 

 ancient granitic substratum to the Taconian series, which appears 

 to be the last of the characteristically crystalline indigenous 

 groups, it being, so far as known, succeeded directly by tha 

 uncrystalline Cambrian, or the equally uncrystalline Kevveenian, 

 which may not, improbably, be itself included in the lower part 

 of the Cambrian series. 



Gastaltii on Italian Geology and the Crystalline Rocks, by T. 

 Sterry Hunt, F.R.S. — The author recalled the fact that, in dis- 

 cussing in 1883 the geological relations of serpentines, he had 

 maintained that, although not confined to Archaean rocks (in 

 which they are found at various horizons), those of Italy, believed 

 by some geologists to be in part of Tertiary age, are, so far as 

 his studies go, wholly Archaean, in accordance with the views 

 set forth by Gastaldi. The serpentines and other rocks of the 

 ophiolitic group existed in their present condition in the seas in 

 which were deposited the Eocene strata, which latter, by sub- 

 sequent terrestrial movements, had been disturbed, broken, and 

 even inverted, so as to seem to pass beneath the ophiolites. The 

 indigenous and neptunian character of serpentines is maintained, 

 while the plutonic hypothesis of their origin has been so far 

 modified by its modern Italian advocates that they now suppose 

 the serpentines to be due to submarine eruptions of a hydrous mag- 

 nesian mud, which subsequently consolidated into serpentine and 

 even into chrysolite. It is difiicult to admit any other than a neptu- 

 nian origin for the stratiform ophicalcites into which the massive 

 serpentines often graduate. In a letter written in July 1878 to the 

 author, but until recently mislaid, Gastaldi showed that the 

 ophiolites of the Ligurian Apennines and of those of Pra to were, 

 like those elsewhere examined by him, protruding portions of 

 the ancient pietre vcrdi zone, identical with that of the Alps, 

 from which the Apennines cannot be distinguished either geo- 

 logically or geographically. The vast series designated by him 

 as \!ici& pietre verdi zone, according to Gastaldi, overlies the ancient 

 central or primary gneiss (generally granitoid, but including 

 quarlzites and crystalline lime-tones with graphite, &c. }, and has 

 a thickness of many thousand metres, embracing three sub- 

 divisions. The lowest of these, sometimes called by him the 

 pie/re verdi proper, includes serpentines, diorites, euphotides, 

 chloritic schists, &c. ; the second is designated by hiua recent 

 gneiss and granite with mica-schists and hornblendic rocks ; 

 while the third consists in great part of soft argillaceous or 

 lustrous schists, with included quartzites, marbles, statuary, and 

 banded dolomites and occasionally also serpentines, the presence 

 of which led Gas'.aldi to include it with the two preceding sub- 

 divisions in his great pietn verdi zone ; a name which the present 

 writer, with Neri and others would re-trict to the lower sub- 

 division, regarded by him as the equivalent of the Iluronian of 

 North .America ; the underlying or central gneiss being the 

 Laurentian ; the recent gneiss and mica-schist, the Montalban or 

 White Mountain series, and the upper subdivision, the Taconian 

 or Lower Taconic of North America ; the wholly distinct Upper 

 Taconic being an uncrystalline series of fossiliferous Cambrian 

 strata. The writer in this connexion recalled the work of Neri, 

 Gerlach, and others in the western Aljis, and that of Von Hauer 

 and his associates in the Lombardo-Venetian Alps, where the 

 same distinction of the irae pieh-e verdi zone between the ancient 

 gneiss below and the recent gneiss above had, unknown to him, 

 been pointed out by the Austrian Geological Survey two years 

 before the present writer in 1870 defined and named the younger 

 gneissic series in North America. The absence of the true pietre 

 verdi series in some localities, alike in the Alps and in North 

 America, between the older and younger gneisses was noted, as 

 well as the existence of apparent discordances between each one 

 of the four great divisions of Archaean or pre- Cambrian crystalline 

 rocks above named. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge. — Mr. A. E. Shipley, of Christ's College, has 

 been appointed Demonstrator of Comparative Anatomy ; Mr, 

 H. F. Newall, of Trinity College, Demonstrator of Experi- 

 mental Physics ; and Messrs. L. R. Wilberforce and H. L. 

 Callendar, both of Tiinity College, Assistant-Demonstrators of 

 Experimental Physics. 



Dr. Peile has been elected Master of Christ's College, an 

 election which all classes of University men, and reformers in 

 particular, rejoice in. 



A novelty is to be introduced in the education lectures next 

 term, Dr. Francis Warner, of the London Hospital, having 

 consented to give a course of six lectures on the physical and 

 physiological study of children. 



I'he next examination for Entrance Scholarships and Exhibi- 

 tions at Gonville and Caius College will begin on December 10, 

 Candidates must be under nineteen on that day. 



Two scholarships of ;^8o, and four others of ^'60 to £^0, 

 will be offered, with exhibitions. Candidates for Natural Science 

 Scholarships may be examined in any of the following subjects : 

 physics, chemistry, biology, and animal physiology, and will be 

 expected to show proficiency in two of them, of which chemistry 

 must be one. The tutors will forward full particulars on 

 application. 



We cannot find space for the long list of lectures in natural 

 science now being given at Cambridge. Prof. Liveing gives a 

 general course of principles of chemistry, and Prof. Dewar 

 lectures on dissociation and thermal chemistry. Prof. Thomson 

 lectures on electricity and magnetism, and on the applications of 

 dynamical principles to physical phenomena. One of the courses 

 of demonstrations at the Cavendish Laboratory is an advanced 

 one on the properties of matter, and on sound. Prof. Lewis 

 lectures on mineralogy. Prof. Stuart on mechanism. Mr. 

 Marr lectures on principles of geology, Mr, Roberts on the 

 palaeontology of Echinoidea, 



Dr. Vines lectures on the physiology of plants (advanced), 

 Mr. Potter on the geographical distribution of plants. 



Prof. Newton lectures on evolution in the animal kingdom ; 

 Mr. Gadow on the morphology of Ichthyopsida (recent and 

 extinct) ; the Curator in Zoology, Mr. Cooke, on the geo- 

 graphical distribution of recent Mollusca. 



Prof. Foster's, Dr. Lea's, and Mr. Langley's physiological 

 courses are as usual. Prof. Macalister gives demonstrations on 

 topographical human anatomy, as well as an elementary course. 



Prof. Cayley's lectures this term are on quaternions and other 

 non-commutative algebras ; Prof. Darwin's on the orbits and per- 

 turbations of planets. Mr, Glazebrook lectures on hydrodynamics 

 (waves and sound) ; Mr. Hobson on spherical and cylindrical 

 harmonics; Mr. Larmor on electrostatics ; Mr. Forsyth on modern 

 algebra (binary forms) ; Dr. Besant on theory of equations and 

 differential and integral calculus ; Mr, H, M. Taylor on higher 

 plane curves ; Mr. Pendlebury on theory of numbers ; Dr. 

 Glaisher on elliptic functions ; and Mr. Steam on elastic solids. 



SCIENTIFIC SERIALS. 

 American Journal of Science, September. — Notes on the 

 geology of Florida, by William H. Dall. In this paper the 

 results are given of two excursions to Southern and Central 

 Florida undertaken in 1885 and 1887 by instruction of the 

 Director of the United States Geological Survey. Special 

 attention is devoted to the process of contemporaneous rock- 

 formation now going on along the Gulf shores of West Florida, 

 and to the Tertiary rocks which prevail so largely throughout the 

 Peninsula. No coral or coral-reef formation was anywhere 

 observed, and it is evident from these further researches that the 

 hypothesis of Agassiz regarding the geological origin of this 

 region can no longer be maintained. — Notes on the deposition 

 of scorodite from arsenical waters in the Yellowstone National 

 Park, by Arnold Hague. The occurrence of this comparatively 

 rare mineral as a deposition from thermal mineral springs is here 

 noticed for the first time. It is found in several localities in the 

 Yellowstone Park as an incrustation deposited from the waters 

 of several hot springs and geysers, and is especially abundant at 

 the Joseph's Coat Springs on Broad Creek, east of the Grand 

 Caiion. The analysis — yielding FcoOg 34'94, AS2O54879, and 

 HjO i6'27 — shows this mineral to be true scorodite, a hydrous 

 arsenate of iron, the layers varying from a mere coating to an 

 eighth of an inch in thickhess. Wherever observed it occurs as 

 an amorphous deposit, and when pure, leek green in colour. — 

 The effects of magnetization on the viscosity and the rigidity of 

 iron and steel, by C. Bams. An attempt is made in this 

 memoir to verify by a static method the results recently com- 

 municated by Mr. Herbert Tomlinson on the changes of viscosity 

 and of elasticity produced by magnetizing iron. It is shown that 

 the increment of rigidity due to magnetization increases at an 

 accelerated rate as the soft, temporarily twisted wire becomes 

 more nearly filamentary. A series of results is also given on the 

 rigidity of mj^netized steel temporarily strained and varyin^j in 

 temper from extreme hard to extreme soft, A main object 

 of the paper is to show how the principles here established may 



