148 



NA TURE 



\June 2 1, 1877 



museum of the Duke of Sutherland by Dr. Joass, of 

 Golspie. These were afterwards analysed by Prof. 

 Heddle, of St. Andrews, and found to be the variety of 

 orthoclase felspar, termed amazonstone. For the pur- 

 pose of more careful examination as to the mode of 

 occurrence of this uncommon substance, Prof. Heddle has 

 recently visited the locality, which is the side of the ridge 

 i-ising to theeast ofthevillage of Tongue. He found the gra- 

 nite masstobe merely a large boulder,and had it thoroughly 

 broken up. It has yielded the following remarkable 

 assemblage of minerals : — amazonstone in simple and 

 twin crystals, radiated cleavlandite, lepidomelane, pinite, 

 fluorite, sphene, zircon, magnetite, ilmenite, allanite, 

 smoky quartz with peculiar faces, and a mineral which a 

 carefully instituted comparison shows to be thorite 

 passing into orangite. The specimens of amazonstone 

 obtained from the boulder are of unparalleled magni- 

 ficence. One which has been sent to the museum of the 

 Duke of Sutherland exhibited a surface of some three 

 square feet, about a dozen large crystals, of which eight 

 were unbroken and perfect. One crystal, unavoidedly 

 broken in the extraction, showed the following extra- 

 ordinary dimensions : — viz., a length of 15J inches, with 

 a breadth and thickness of ten and eight inches respec- 

 tively. The minute structure of these crystals is pecu- 

 liar, and has been fully described in a recent paper by 

 Dr. Heddle on Scottish felspars in the Transactions 

 of the Royal Society of Edmburgh. The exceed- 

 ingly rare thorite was found in only a small quantity. 

 From an examination of the granite of this and other 

 boulders on the same hill, it appears that they have pro- 

 bably come from the huge mass of Ben Laoghal, which 

 lies a few miles inland to the south-west. Should this be 

 their origin, we may expect yet to find new sources of 

 amazonstone, and perhaps other rare minerals among 

 the numerous corries and crags of that picturesque 

 mountain. 



Tertiary Leaf- beds of Cot.orado. — Mr. E. L. 

 Berthoud, of the Terricorial School of Mines, Golden 

 City, Colorado, sends notes of a section near that place 

 which presents some considerable resemblance to the 

 sections in Antrim and Mull, where the miocene leif- 

 beds and lignites are associated with sheets of basalt 

 and tuff. The order of succession is as follows : — 



Basalt 



Lignite and leaf-bed 



Hard mud ly clay and sandstone 



Second leaf-bed 



Clay, sandstone, conglomerate 



Third small leaf-bed in clay 



Sandstone and clay, &c. 



Basalt 



lio feet 



the result is fatal to the young cod and other fry which 

 then seek the coasts in search of food. He states that 

 vast multitudes of the young fish are, from this cause, 

 destroyed every summer and autumn in the bays and 

 fjords, and he accounts for changes which have taken 

 place in the migratory movements of seals by this whole- 

 sale destruction of the f9od which they used formerly to 

 find in the coast-waters. He recommends the utilisation 

 of the offal, which would not only eventually prove re- 

 munerative as a source^ of artificial manure, but would 

 remove the poisonous gases which are set free on the 

 melting of the anchor-ice at a time when they cannot fail 

 to prove highly destructive. 



Origin of the Trees and Shrubs in the South 

 OF France. — In a recent memoir presented to the 

 Academy of Sciences of Montpellier, the veteran pro- 

 fessor Charles Martins discusses the history of those 

 trees and shrubs in the south of France which suffer from 

 severe cold, such as the carob-tree, oleander, European 

 palm, myrtle, sweet-bay, pomegranate, olive, fig, laurus- 

 tinus, ilex, vine, and others. He shows that most of these 

 occur among the tertiary and quaternary deposits, that 

 some of them, indeed, like the oleander (Ncrium oleander), 

 go back even into eocene times. He points to the fact 

 that their remains occur in the geological formations, not 

 only of the countries where the plants are still living, but 

 even of tracts considerably further to the north, both in 

 France and in Switzerland, where their living descendants 

 or analogues could not endure the severity of winter now. 

 The tender trees and shrubs of the Mediterranean sea- 

 board thus serve to prove the former wanner climate of 

 France and its subsequent refrigeration. They are merely 

 the surviving relics of a tertiary vegetation preserved by 

 the exceptional mildness of the climate in which they 

 grow. A single winter of exceptional rigour, or even a 

 single night of extreme cold, like that of January 13, 

 1826, when the thermometer fell to 9°7 below zero (Cent.), 

 would suffice ta destroy them. It may be presumed, how- 

 ever, that during at least the height of the glacial period 

 these tender plants were driven southwards beyond their 

 present northern limits, and that they have subsequently 

 crept north again. 



The resemblance is further borne out by Mr. Ber- 

 thoud's list of plants, which includes Platanus aceroides, 

 Filicites hebridica, Populus arctica, Corylus lMc(2narii, 

 FagHS macrophylla, (2uercus chlorophylla, Sequoia, sp. (?), 

 Gymnogramina Haydeni, Cinnamomiim, n. sp., Ficus, 2 sp. 

 nov., Ma^iio/ia, 2 sp , yiiglans, 2 sp., Sabal Campbellii, 

 S. Gray ana, and S.gvldiamis, Myrica, &c. 



Influence OF Anchor-Ice UPON Fishing-Grounds. 

 — Prof. Hind, to whose late researches in Labrador we 

 recently called attention, has published some remarks on 

 the effects of the formation of ground-ice in retarding the 

 decomposition of fishoffal, and thereby in seriously 

 damaging the value of the Labrador fishing-grounds. He 

 shows that the ice formed on the sea-bottom freezes the 

 offal, and protects it from being devoured by sea- 

 scavengers and from decomposition ; that every rise in 

 temperature which prevents the formation of anchor-ice 

 promotes the decomposition of the offal ; that when this 

 takes place, as it does every year under a covering of 

 surface-ice, the water, not being aerated, becomes foul 

 with gases and from the removal of its oxygen, and that 



U.S. NATIONAL ACADEMY OF SCIENCES 

 A CCORDING to the terms of its charter from Congress, the 

 ■'"^ National Academy of Sciences must hold its annual meet- 

 ing in April, at Washington. It holds also a semi-annual 

 meeting in the autumn. Its membership has been very slowly 

 increasing, till now it numbers nearly, if not quite, lOO. At the 

 last meeting, April 17-20, Prof Henry presided. The Academy 

 resolved to present a memorial to Congress, in favour of the 

 eijtablishment and maintenance of an International Bureau of 

 Weights and Measures with the object of promoting permanence, 

 precision, and uniformity in the standards, by the joint action of 

 the leading powers of the world, according to the convention 

 submitted to the Senate. 



Five new members were elected : — Prof. John W. Draper and 

 Dr. Henry Draper of New York, Dr. Elliot Coues of Wash- 

 ington, Dr. S. H. Scudderof Cambridge, Mass., and Mr. Charles 

 S. Peirce of the U.S. Coast Survey. 



The annual report of the president, Prof. Henry, recounts 

 briefly the year's work of the Academy. The Academy reports 

 progress in the work of preparing and pubhshing the scientific 

 results saved from the wreck of the Polaris and in general con- 

 tributed by the expedition in which that vessel was engaged. 

 This work is in the hands of Dr. Emil Bessels, the scientihc 

 diector of the expedition, and will be finished in three quarto 

 vjlumes. The first volume is already published ; it is a quarto 

 of 960 pages relating to astronomy, pendulum experiments, 

 winds, solar radiation, and meteorology in general. It is illu?- 

 tiated by fourteen plates, two maps, and lorty woodcuts ; only 

 500 copies of this volume were printed. The second and third 

 volumes relate to geology, pala'ontology, mineralogy, botany, 

 zoology, and ethnology. They will include a monogr..ph on the 

 Eskimo, illustrated by 100 piates and 200 woo 1 cuts. The 

 Academy has divided the income from the Bache fund, so as to 



