March 8, 1894] 



NATURE 



451 



analytical determination of probably available "mineral " plant 

 food in soils, by B. Dyer. The author has made a series of de- 

 terminations of the average acidity of the root sap of about loo 

 plants in order to measure the power of dissolving the mineral 

 constituents of soils possessed by plants. These experiments 

 seemed to indicate the suitability of a i per cent, solution of 

 citric acid as an analytical soil solvent ; the effect of this solu- 

 tion on a number of the Rothamsted soils was therefore tried. 

 The conclusion is drawn that valuable indications of compara- 

 tive ("mineral ") soil fertility are obtained by the use of such a 

 solution. After the reading! of the paper, Sir Henry Gilbert 

 gave a short sketch of the development of soil analysis. — The 

 behaviour of the more stable oxides at high temperatures. Part 

 ii., by A. A. Read. At 1750', SboOj is converted into Sb.j03, 

 VjOg into V2O3, and FcoOj into Fcgbj, whilst the oxides of cobalt 

 and nickel are reduced to the metallic state. — The stability of 

 the oxides considered in relation to the periodic law, by G. H. 

 Bailey. In the even series of the periodic classification, the 

 oxides are more stable the higher the atomic weight of the 

 element concerned, the temperature of decomposition being 

 taken as an index of stability ; in the odd series the oxides be- 

 come less stable as the atomic weight increases. — The inter- 

 action of benzil and benzylamine in presence of zinc chloride: a 

 preliminary note, by F. R. Japp and W. B. Davidson. On 

 heating benzil, benzylamine, and zinc chloride together at 100°, 

 tetraphenylazine, benzyllophine, and dibenzyllophinium chloride 

 are obtained. 



Geological Society, February 16. — W. H. Hudleston, 

 F.R.S., President, in the chair.^ — ^The Wollaston medal was 

 awarded to Geheimrath Dr. Karl Alfred von Zittel, professor of 

 geology and palaeontology in the University of Munich, in recog- 

 nition of the important services which he has rendered to palason- 

 tologicalscienceduringalong period of time. — Mr. Aubrey Strahan 

 was awarded the balance of the proceeds of the Wollaston Don- 

 ation Fund, in token of appreci'ation of his geological work in 

 several parts of England and on the Welsh border. — Mr. William 

 Talbot Aveline received the Murchison medal, together with a sum 

 of ten guineas, in recognition of the importance of his work as a 

 geological surveyor. — The balance of the proceeds of the Mur- 

 chison Geological Fund was handed to Mr. George Barrow, as a 

 testimony of the value of his geological work both in Yorkshire 

 and in Scotland. — -The Lyell medal, with the sum of ^46, 

 was awarded to Prof. John Milne, F.R, S., of the Imperial 

 College of Engineering, Tokio, Japan, in testimony of ap- 

 preciation of his investigations in seismology. — The balance of 

 the proceeds of the Lyell Geological Fund was presented to Mr. 

 William Hill, in testimony of the value of his work amongst the 

 Cretaceous rocks of this country during the last eight years. — A 

 sum of £2'^ from the proceeds of the Barlow-Jameson Fund was 

 given to Mr. Charles Davison, in token of appreciation of his 

 work in geological dynamics, including under that term the study of 

 earthquakes. — The President then read his anniversary address, 

 which may be summarised as follows : — In continuation of the 

 subject of the preceding anniversary address, relating to some 

 recent work of the Geological Society, the remaining portion of 

 the papers contributed within the septennial limits is classified 

 under two groups. In the first group are placed papers de- 

 scriptive of the newer palaeozoic rocks, the older palaeozoic 

 rocks, and the fundamental rocks, and on general petrology, 

 which relate more especially to the geology of the British Isles. 

 This group is considered in detail, and constitutes the bulk of 

 the address. In the second group are placed numerous papers 

 which may roughly be classified under the following headings : 

 — Miscellaneous geology, foreign and colonial — a somewhat 

 exhaustive division, comprising about a score of papers, dealing 

 with many .'-ubjects in different parts of the world. African 

 geology, especially, comes to the front in this group. Miscel- 

 laneous invertebrate palaeontology — a score of papers may be 

 thus classified. Most of these matters are for the consideration 

 of specialists, relating to corals, crinoidea, bryozoa, ostracoda, 

 cephalopoda, and to siliceous organisms. In palaeobotany there 

 has only been one paper of any importance ; whilst under the 

 heading dynamical problems are a few papers dealing with the 

 movement of material. A notice of the Inverness earthquake, 

 and a communication on the origin of the basins of the great 

 lakes of America, complete this category. The detailed con- 

 sideration of the first group commences with the newer 

 palaeozoic rocks. The carboniferous system has not yielded any 

 important stratigraphical papersof late years, but there have been 

 some interesting communications respecting the coal measures. 



NO. I 27 I, VOL. 49] 



Questions as to the origin and faunal character of these are dis- 

 cussed by more than one writer, and very impirtant deductions, 

 as to the delimitation of the marine and freshwater beds, have 

 been drawn. The subject of coal in the south-east of England 

 was considered, a propos of a paper read at the Society some 

 years ago, and the prospects of coal-getting at Dover and else- 

 where in this part of England discussed. In Devonian geology, 

 the structure and peculiarities of the South Devon limestones 

 form the subject of an interesting communication ; and there are 

 also important stratigraphical papers in this connection, more 

 especially one written subsequent to the visit of a party from the 

 International Geological Congress of London. In the older 

 palaeozoic rocks a considerable amount of work has been done, 

 more especially amongst the Silurian and Ord ivician of the north- 

 west of England, where additional evidence has been furnished 

 of the value of graptolite-zones as a means of comparison with 

 the older palaeozoics of distant areas ; and a further contribution 

 has also been made to our knowledge of beds of this age in the 

 Cross-Fell inlier. The papers dealing with the fossiliferous 

 Cambrian are not numerous, but they are of great importance, 

 including the recognition of a very low Cambrian fauna at the 

 top of the Penrhyn quarries, and Sir J. W. Dawson's correlation 

 of American with European Cambrians. The discovery of 

 0/eneI/us in the "fuoid beds" of the north-west Highlands also 

 serves to fix the Cambrian age of the Durness limestone, to which 

 formation the altered limestone of Strath in Skye, at one time 

 regarded as of Liassic age, is now held to belong. The physical 

 relations and the post-Cambrian metaiporphism of the rocks of 

 the north-west Highlands are also considered under this heading. 

 The fundamental rocks are roughly divided into three categories, 

 viz. the sedimentary series, the volcanics, and the crystalline 

 schists. The first includes the Torridon sandstone, the Long- 

 mynd rocks, the unfossiliferous Cambrians of Wales, &c. The 

 volcanic series has already formed part of the subject of an 

 address from the chair. Oddly enough, the best defined pre- 

 Cambrian, or fundamental sediaientary series, is to be found in 

 the north-west Highlands, a district which only a few years 

 ago was an enigma, but which we hope may now supply a clue 

 to regions more obscure. This, of course, is the Torridon 

 sandstone, which has a well-defined base and a well-defined 

 summit. Then there are certain rocks which some regard as 

 Cambrian, others as pre-Cambrian, such as the Howth Hill 

 and Bray Head beds, claimed as Upper Monian. Cross- 

 ing St. George's Channel, we find ourselves in Anglesey, a 

 land of pre-Cambrian mysteries. The older rocks have been 

 described as belonging to the Monian system, an arrange- 

 ment much controverted, and this controversy has extended to 

 Shropshire. Lastly, there is the long-standing contention as to 

 whether the unfossiliferous Cambrians of North Wales really 

 belong to that system or should be placed on a lower horizon. 

 The Malvernian controversy relates, in the main, to the crystal- 

 line schists. Under the heading of General Petrology is grouped 

 a very large series of papers, more than sixty in number, divided 

 roughly into two primary classes, according as they relate to the 

 British Isles or to foreign countries, the former class being 

 alone considered in detail. The arrangement is topographical, 

 and the rocks under this heading may be of any age from the 

 Archaean upwards. Scotland has yielded seven papers in this 

 group — most of them of very great interest and importance, one 

 or two being somewhat controversial. The subject of contact- 

 metamorphism is raised with reference to more than one Scotch 

 locality ; and from the Lake District there has been a communi- 

 cation on the Shap granite and associated igneous and metamor- 

 phic rock, which again brings this question into prominence. 

 Some of the papers relating to Wales have already been dealt 

 with in a previous address, but the subjects of the variolite and also 

 of the nodular felstones of the Lleyn are noticed on the present 

 occasion. In Devonshire the rocks formerly known as " fel- 

 spathic traps " have been described as basalts and andesites ; 

 whilst the igneous origin of the Dartmoor granite has been 

 maintained against one of those theories which from time to 

 time crop up with respect to this well-known massif. Allusion 

 is also made to the controversy with respect to the Start rocks. 

 There have been four papers dealing with the Lizard peninsula, 

 in which questions as to priority of the several igneous masses 

 and as to the origin of the banded gneisses are entertained. It 

 cannot be doubted that considerable progress has been made of 

 late towards a recognition of the true character of these rocks, 

 which, for the extent of territory they occupy, are perhaps with- 

 out equal in point of interest throughout the British Isles. The 



