3t6 



NATURE 



\Aug. 19, 1875 



the more delicate of them dreappear, in the transition from 

 the calcareous ooze to the ' red clay ; ' and it is only by 

 this light of later observations that we are now aware that 

 this is by no means necessarily the case. On the 23rd of 

 March, 1875, in the Pacific, in lat. 11° 24' N., long. 

 143° 16' E., between the Carolines and the Ladrones, we 

 sounded in 4,574 fathoms. The bottom was what might 

 naturally have been marked on the chart ' red clay ; ' it 

 was a fine deposit, reddish brown in colour, and it con- 

 tained scarcely a trace of lime. It was different, how- 

 ever, from the ordinary ' red clay,' — more gritty — and the 

 lower part of the contents of the sounding tube seemed to 

 have been compacted into a somewhat coherent cake, as 

 if already a stage towards hardening into stone. When 

 placed under the microscope, it was found to contain so 

 large a proportion ofthetestsof Radiolarians, that Murray 

 proposes for it the name * Radiolarian ooze.' This obser- 

 vation led to the reconsideration of the deposits from the 

 deepest soundings, and Murray thinks that he has every 

 reason to believe (and in this I entirely agree with him) 

 that, shortly after the 'red clay' has assumed its most 

 characteristic form, by the removal of the calcareous 

 matter of the shells of the Foraminifera, at a depth of say 

 3,000 fathoms, the deposit begins gradually to alter again 

 by the increasing proportion of the tests of Radiolarians, 

 until, at such extreme depths as that of the sounding of 

 the 23rd of March, it has once more assumed the cha- 

 racter of an almost purely organic formation, the shells 

 of which it is mainly composed being however in this 

 case siliceous, while in the former they were calcareous. 

 The * Radiolarian ooze,' although consisting chiefly of the 

 tests of Radiolarians, contains, even in its present condi- 

 tion, a very considerable proportion of red clay. I 

 beheve that the explanation of this change, which was 

 suggested by Murray, and was indeed almost a necessary 

 sequence to his investigations, is the true one. We have 

 every reason to believe, from a series of observations, as 

 yet very incomplete, which have been made with the tow- 

 net at different depths, that Radiolarians exist at all 

 depths in the water of the ocean, while Foraminifera are 

 confined to a comparatively superficial belt. At the sur- 

 face and a little below it, the tow-net yields certain 

 species ; when sunk to greater depths, additional species 

 are constantly found, and, in the deposits at the bottom, 

 new forms occur, which are met with neither at the sur- 

 face nor at intermediate depths. It would seem also that 

 the species increase in number, and that the individuals 

 are of larger size as the depth becomes greater ; but many 

 more observations are required before this can be stated 

 with certainty. Now, if the belt of Foraminifera which, 

 by their decomposition, according to our view, yield the 

 ' red clay,' be restricted and constant in thickness, and 

 if the Radiolaria live from the surface to the bottom, it is 

 clear that, if the depth be enormously increased, tbe accu- 

 mulation of the Radiolarian tests must gain upon that of 

 the ' red clay,' and finally swamp and mask it," 



Prof. Wyville Thomson further informs me that the 

 best efforts of the Challenger's staff have failed to dis- 

 cover Dathybius in a fresh state, and that it is seriously 

 suspected that the thing to which I gave that name is 

 little more than sulphate of lime, precipitated in a floccu- 

 lent state from the sea-water by the strong alcohol in 

 which the specimens of the deep-sea soundings which I 

 examined were preserved. 



"The strange thing is, that this inorganic precipitated 

 is scarcely to be distinguished from precipitated albumen, 

 and it resembles, perhaps even more closely, the proli- 

 gerous pellicle on the surface of a putrescent infusion 

 (except in the absence of all moving particles), colouring 

 irregularly but very fully with carmine, running into 

 patches with defined edges, and in every way comporting 

 itself like an organic thing." 



Prof. Thomson speaks very guardedly, and does not 

 consider the fate of Bathybius to be as yet absolutely de- 



cided. But since I am mainly responsible for the mistake, 

 if it be one, of introducing this singular substance into the 

 list of Hving things, I think I shall err on the right side in 

 attaching even greater weight than he does to the view 

 which he suggests. T. H. Huxley 



THE INTERNATIONAL CONGRESS AND 

 EXHIBITION OF' GEOGRAPHY 



AT the distribution of prizes the Ordnance Survey 

 obtained a letter of distinction, although it was not 

 an exhibitor. It is the only instance in which such an 

 honour was awarded. M, Quatrefages, in the name of 

 the governing body of the society, awarded two excep- 

 tional prizes, one to MM. Payer and Weyprecht for the 

 discovery of Francis-Joseph Land, and the other to M. 

 Delaporte for the foundation of the Cambodian Museum 

 at Compiegne. Admiral la Ronci6re, Je Nourry closed 

 the meeting by a very impressive address reviewing the 

 characteristics of the Congress. 



The success of the Exhibition is so great that it will be 

 kept open up to the 19th of September. The number of 

 visitors is greater than ever now that the Congress is 

 over, and many fresh attractions have been added to 

 several sections. M. Buys Ballot, the director of the 

 Utrecht Meteorological Institution, has sent a board used 

 by him for better indicating the direction of winds and 

 distribution of pressure. Small holes are perforated in a 

 map at the places occupied by the several stations. In 

 these holes are placed small needles whose height indi- 

 cates the barometrical height, and whose head is an arrow 

 showing the actual direction of the wind. 



In the French annexe has been exhibited a drawing of 

 a machine for manufacturing relief maps out of a block 

 of plaster. The knife is movable by a kind of pantograph, 

 and can be conducted alongside the several lines of level 

 (lignes de niveau) of a map which is seen by reflection in 

 a plate of glass placed in a suitable position. 



Peter the Great having been appointed a member of 

 the Academy of Paris in 1717, ordered a map of the Cas- 

 pian Sea to be drawn, which he sent to his fellow-members 

 of the Academy as a proof of his zeal for the progress of 

 science, and to justify the honour which had been con- 

 ferred upon him. This map was lodged in the archives 

 of the Academy, engraved and published in the volume 

 of 1 72 1, with a report written by Dellile the astronomer. 

 It happens that the same map is exhibited at the Russian 

 annexe, and the circumstances connected with it having 

 become generally known, it has given rise to the report 

 that the Grand Duke Constantine will be elected a mem- 

 ber of the Academy, like his ancestor and the Emperor 

 of Brazil. It is something more than an idle rumour. 



A banquet was given by the Section of Commercial 

 Geography, and some resolutions were adopted l7iter 

 poculas. The most notable is in reference to the estab- 

 lishment of a/w^i/rt in the centre of the Sahara for the 

 use of all civiHsed nations. But although adopted unani- 

 mously, the motion is not likely to be carried into execu- 

 tion very speedily. 



SCIENCE IN GERMANY 

 {From Germafi Correspondents.) 

 T T was the phenomenon of the motion of glaciers which 

 •^ caused most of the scientific men, that studied its 

 details, to make experiments on the behaviour of snow 

 and ice under pressure. The brothers Von Schlagintweit 

 and Prof. Tyndall were the first who made such expe- 

 riments with regard to glacial phenomena. Later on 

 Helmholtz described a series of investigations', which 

 proved amongst other things that snow is changed into 

 ice by high pressure, that ice broken into little pieces can 

 again be pressed into a homogeneous ice cylinder, that 



