May II, 1876] 



NATURE 



39 



along the earliest channel of the Dee, which would be at an ele- 

 vation from 1,300 to 1,400 feel higher than the present channel. 

 During the Glacial epoch ice-action deepened, and more or less 

 modified the existirig channel, and scooped out the basin of Bala 

 Lake, which was not previously in existence. The general 

 results of this investigation are as follows : — After the last im- 

 portant disturbance of the pre-Permian rocks, North Wales was 

 carved slowly and by sub-aerial agencies into its present 

 mountainous form, chiefly between Permian and Preglacial 

 times. The work of the glaciers of the latter period somewhat 

 deepened, widened, smoothed, and striated the minor outlines 

 of the mountains and valleys, and excavated many rock-bound 

 lake-basins, but did not effect any great changes in the contours 

 of the country. A minor submergence of part of Britain during 

 part of the Glacial epoch produced no important effects on the 

 large outlines of the rocky scenery ; and the effects of sub-aerial 

 waste subsequent to the Glacial epoch have been comparatively 

 small. — On the Ancient Volcano of the District of Schemnitz, 

 Hungary, by Mr. John W. Judd. The old volcanoes of Hun- 

 gary have long been known to present some very interesting 

 illustrations of the relations between the igneous rocks erupted 

 at the surface, and those which have consolidated at a con- 

 siderable depth beneath it. The district in which these pheno- 

 mena can be best studied is that of Schemnitz ; but although 

 this area has been very carefully mapped and explored by a 

 number of able investigators, the greatest diversities of opinion 

 still exist concerning the relations of certain of the rock-masses 

 exposed within it. Over an area nearly fifty miles in diameter 

 enormous accumulations of dndesite and quartz-andesite lavas and 

 agglomerates have been erupted, these now forming a group of 

 mountains rising from 3,000 to 4,000 feet above the sea -level, 

 and culminating in a great ring of precipitous heights overlook- 

 ing a depressed central area of oval form, the site of the famous 

 mining towns of Schemnitz, Kremnitz, and Konigsberg. In the 

 midst of this depressed central area there occurs a considerable 

 development of rhyolitic lavas and tuffs, and more scattered 

 outbursts of basalt. From the magnificent floras associated with 

 the various volcanic tuffs, we know that the andesitic rocks were 

 erupted during the earlier portion of the Upper Miocene period 

 and the rhyolitic towards its close, while the basalts are pro- 

 bably of as late date as the Pliocene. Besides the rhyolites and 

 basalts, however, there are certain other rocks exposed in the 

 central area of the Schemnitz district, the relations of which it is 

 very difficult to understand. These consist of (i) strata of Lower 

 Trias and Nummulitic age, through the midst of which the vol- 

 canic outbursts have evidently taken place ; (2) masses of highly 

 metamorpliic rocks, including quartzites, crystalline limestones, 

 various schists, gneiss and aplite ; and (3) undoubted eruptive 

 rocks, which have usually been called " syenite and granite," 

 but for which the names of " diorite and quartz-diorite " would 

 perhaps be more appropriate, inasmuch as the prevailing felspar 

 in them is always a plagioclase variety. By Beudant and other 

 early writers the andesitic lavas were recognised as volcanic pro- 

 ducts of a comparatively recent geological period, while the 

 "granite, syenite, and greenstone," were regarded as being of 

 far more ancient date. By von Pettko, Richthofen, and all the 

 more recent investigators of the district, however, it has been 

 clearly perceived that the "greenstones" are certainly, like the 

 andesites, of Tertiary age, and hence such names as " green- 

 stone-trachyte " and "propylite" have been applied to them. 

 The studies of the author of the present memoir, both in the 

 field and in the cabinet, have led him to the conclusion that the 

 granitic, porphyritic, and lava rocks — which were formerly called 

 " syenite," "greenstone," and "trachyte "respectively — areall of 

 similar composition and equivalent age, and that they differ only 

 in their more or less perfect state of crystallisation, the result 

 evidently of variations in the conditions under which they have 

 consolidated. He is further led to regard the metamorphic 

 masses, around the several intrusive centres as being not, as has 

 hitherto been maintained, of "Primary" (Devonian or Permian) 

 age, but simply Triassic rocks affected by local or contact meta- 

 morphism. The real structure of the great Schemnitz volcano 

 was first recognised by von Pettko in 1848, though this author 

 erroneously regarded it as presenting an example of a " crater of 

 elevation." The history of the formation and destruction of this 

 volcano is now shown to be as follows : — After some small and 

 scattered outbursts of rocks of acid composition towards the 

 close of the Oligocene period, the grand eruptions of andesitic 

 lavas of the Miocene began, through the agency of which a 

 volcano of larger dimensions than Etna was gradually built up, 

 by both central and lateral eruptions. In the midst of this 



volcano a crater of enormous dimensions was formed, doubtless 

 by some great paroxysmal outbreak, and by the subsequent 

 subsidence of the mountain the sea gained access to, and by 

 denudation greatly enlarged the area of this " Caldera." Then in 

 the central lagoon of the caldera a number of minor eruptions, 

 first of acid and then of basic rocks took place ; and the volcano, 

 which at this period of its history must have closely resembled 

 the existing island of Santorin, was again upheaved from beneath 

 the sea, and exposed to the wasting effects of subaerial denudation. 

 The gradual decline of the volcanic forces in the distrct was 

 marked, as is usually the case, by the appearance of hot and 

 mineral springs, discharges of gas, occasional earthquakes, &c. 

 While affording such remarkable examples of the perfect tran- 

 sition between the so-called plutonic and the voicanic classes of 

 rocks, and of the phenomena of com act meiamorptiism, the gra- 

 nitic masses of the Schemnitz district are wiihout question truly 

 intrusive ; and a careful study of them lends no support what- 

 ever to the hypothess that such rocks may be formed by the 

 extreme metamorphism of sediments in situ. There is the most 

 complete proof that in the Schemnitz district the formation of 

 true mineral veins, containing gold, silver, and other metals, has 

 taken place within the most recent geological periods ; in some 

 cases, indeed, at a later date than the Pliocene. 



Institution of Civil Engineers, April 25. — The first paper 

 read was descriptive of the " Dhn Heartach Lighthouse," by Mr. 

 David Alan Stevenson, B.Sc. — The second paper read was " Oii 

 the changes in the tidal portion of the river Mersey, and in its 

 Estuary," by Mr. James N. Shoolbred, B.A., Assoc. Inst., 

 C.E. 



May 2. — Mr, George Robert Stephenson, president, in the 

 chair. — The paper read was on fascine work at the outfalls of 

 the Fen Rivers, and reclamation of the foreshore, by Mr. W. 

 H. Wheeler, M. Inst. C.E. 



Berlin 



German Chemical Society, Feb. 28. — A, W. Hofmann, 

 president, in the chair. — H. Ritthausen described a crystalline 

 constituent of vicia saliva vicin,. CgH^gNsOg, which, treated 

 with sulphuric acid, yields a sulphoconjugated acid, exhibiting 

 blue reactions with baryta water and ammonia. — R. Schiff had 

 transformed chloraechyl-aldehyde by heating it with acetate of 

 potassium into the diacetate of ethylidene. The former body is 

 therefore chlori-acetate of ethylidene^ 



C Hg— CH. CI— O— CO— CH3. 

 — R. Bartb, by treating resorcine with hydrochloric acid, has 

 produced an anhydride of resorcine, CgH^OH.O.CgH^OH, a 

 dichroic substance, green in reflected light and red in solution. — 

 O. Wilf published considerations on the constitution of organic 

 dyes. — M. Nencky has found indigo in the urine of dogs fed with 

 indol. — A. Oppenheim reported on various researches on aceto- 

 acetic ether. Together with H. Precht, he has simplified the 

 method for obtaining this substance in large quantities. The 

 vapour density has been taken, and it has been explained why 

 no hydrogen is evolved during the action of sodium on acetic 

 ether ; the reason being the transformation of acetyl, CH3CO, 

 into oxethyl, CHjCHjO. The same chemists have discovered 

 a practical method for obtaining dehydracetic acid, CgH804, by 

 passing aceto-acetic ether through heated iron tubes. They 

 described its ethyl-compound and the action of potash on dehy- 

 dracetic acid : C8H8O4 + sHjO = 2C2H4O, (acetic acid) + 

 CgHgO (acetone) + COj. Baryta forms at the same time a 

 substance resembling orcine. The same chemists found acetic 

 ether, when heated, to yield ethylene and acetic acid. — A. 

 Oppenheim and C. Emmerling have studied the action of oxy- 

 dising agents on oxyuritic acid. The result is an acid, CyHgOg, 

 to which they give the name of hydro-oxybenzoic acid. By 

 fusion with potash, it yields benzoic acid and water. 



March 13. — A. W. Hofmann, president, in the chair. — Dr. 

 Radziszewsky has transformed phenylacetic acid 



CgHo . CH2 . COOH 

 into the corresponding aldehyde and alcohol j'^rphenyl-ethyl- 

 alcohol CgHo , CHg . CHgOH, Uquids boiling at 207° and 212°; 

 — F. Salomon has compared the properties of oxalurate of ethyl 

 obtained by synthesis from urea with chloro-oxalate of ethyl 

 with that obtained from oxalurate of silver. He Tias found 

 them identical in the properties. Amongst other reactions he 

 remarks that both with oxide of silver yield parabanate of silver. 

 — V. Meyer and several of his pupils revert to the reaction 

 which mixed azocompounds : — 



