192 



NATURE 



[Dec. 25, 1879 



has nothing— as Mitchell asserted— to do with its solubility or 

 compressibility. Jitst as little practicable is the chemical hypothesis 

 upon what takes place in caoutchouc, and the absorption 0/ gases 

 such as nitrous oxide, carbonic acid, and hydrogen by caoutchouc 

 must be considered as a purely physical phenomenon. A layer of 

 caoutchouc is, then, to be conceived as a porous substance, 

 endowed with powers of condensing as well as of rarefying gases 

 whose porosity is of the same order as the porosity of graphite. 

 The motion of the gas takes place through the pores of the 

 caoutchouc. 



It is much to be regretted that Graham's experiments upon the 

 passage of gases through metals were so conducted, that they 

 cannot now be calculated with the help of the laws of the 

 diffusion of gases in absorbent substances. I have been able to 

 calculate only those numbers which, as they are not without 

 intere-t, I will here communicate. They are the constant D 

 for hydrogen in platinum at bright red heat, aud D for car- 

 bonic oxide and hydrogen in iron at full red heat. 



A platinum wire absorbed at red heat C17 volumes of hydro- 

 gen (taking the average of four experiments). A tube drawn 

 out of the same mass of fused platinum, o'li centimetres in 

 diameter, let 489-2 cubic centimetres of gas in the minute pass 

 through a surface of 1 square metre ; therefore 



Z> = o'ooo53 — . 



• sec 



A tube of malleable iron, 0^17 centimetres in diameter, let C284 

 cubic centimetres of carbonic oxide and 76-5 cubic centimetres of 

 hydrogen through the square metre in the minute. Since one 

 volume of this metal can contain four volumes of carbonic oxide, 

 so is for this gas 



cm 2 



D = 0*00000002 . 



sec 



Since the coefficient of absorption of this metal for hydrogen 

 was less than four, so is the constant D for this gas greater than 



croooorxKd c —, whence it follows, if there can be any corn- 

 sec 

 parison between these two numbers, that in metals greater con- 

 stants D belong to specifically lighter gases. 



It has lately been asserted by Stefan that the constant D, in 

 both water and alcohol, is greater for oxygen and nitrogen than 

 for carbonic acid, and that the greatest constant pertains to 

 hydrogen. It would be, however, premature to wish to draw 

 from his experiments any conclusions with regard to the nature of 

 absorption of gases in fluids. 



Franz Exner has already shown, several years ago, that, on 

 the passage of gases through a lamina consisting of a solution of 

 soap in water, the interchanged volumes of two gases are directly 

 proportional to their coefficients of absorption aid in inverse ratio 

 to the square root of their specific gravities. Hence Stefan has 

 concluded that the constant D in fluids is in inverse ratio to the 

 square root of the specific gravity of the gas, and that the gas 

 molecules move by themselves and not in connection with the 

 molecules of the fluid, which would correspond with Dalton's 

 views on the nature of absorption in fluids. Meanwhile, these 

 conclusions are contradicted by the experiments of Pranghe, 

 who has shown that the above-mentioned relation in the case 

 of the lamina is not at all borne out when pure unboiled linseed 

 oil is used. We see from this, then, that what takes place in 

 the case of fluids must be much more complicated, and that we 

 must subject the matter to a much more searching and extended 

 inquiry before we shall be in a position to say anything definite 

 upon the nature of the absorption of gases in liquids. 



S. Wroblewski 



Waatsch. They may be ascribed with great probability to the 

 Taurisci, a Celtic tribe, known to have worked the salt at Hall- 

 stadt, and to have extended from Upper Austria, through Styria 

 and Carinthia, as far as the Julian Alps. Strabo asserts ex- 

 plicitly that the very ancient landing-place Nauportus (now 

 Ober-Laibach) was a settlement of this people, and, according 

 to him, Italian merchandise was brought by carriage from 

 Aquileja over Mount Okra (now Birnbaumer Wald), then by the 

 River Savus to Siscia (now Sissek) and the Danubian districts. 

 Thus it must be admitted that before the reign of Augustus a 

 much-used water-communication existed on the Save and the 

 Laibach between Siscia and Nauportus. The tradition ascribing 

 the foundation of Emona to the Argonauts is an indication of 

 the very remote beginning of this intercourse. Prof. Mullner, of 

 Marburg, has lately offered some forcible arguments to the effect 

 that Emona did not occupy the present position of Laibach, but 

 was at the south end of the Laibach Moor, where Brundorf and 

 Sonnegg now stand. 



The graves, with skeletons, at Roje, near Morants, contain 

 objects referable to the Merovingian Period (fourth to seventh 

 centuries) ; and a skull from one of them is of the type of those 

 found in the successional sepultures. 



NOTE ON PREHISTORIC STATIONS IN 

 CARNIOLA 1 

 nPHE most important of these prehistoric stations is the burial- 

 *■ field of Klenik, near Waatsch. During the year 1S78 

 about 250 graves, covered with stone slabs, were opened at a 

 depth of from \ metre to z\ metres. They contained skeletons, 

 some remains of burnt corpses, and a great number of various 

 objects. The bronze and other articles are very similar to those 

 found in the well-known cemetery near Hallstadt, in Upper 

 Austria. No Roman remains were met with. Thus there is no 

 doubt of the pre-Roman age of these stations and cemeteries near 



1 From the First Report of the Prehistorical Committee of the Vienna 

 Academy, with 22 plates. By F. von Hochstettpr and Ch. Deschmann. 

 (Proceedings, Imper. Acad , July 3, 1879.) 



GEOLOGY OF GREECE 



1. The Thessalian Olympus. — In treating of the geology 

 of Greece, as determined by a recent survey, Herr M. Neu- 

 mayr, in the Proceed. Imper. Acad. Sciences, Vienna, July 

 17, 1879, describes this mountain-group as having a north 

 and south direction, and consisting of a somewhat flattened 

 dome of strata, with a subordinate syncline on the west. 

 The limits on both sides are defined by lines of fracture. 

 The constituent rocks are schists, of many kinds, with enormous 

 intercalated limestones, at some places 3,000 metres thick'. These 

 latter are partly saccharoidal, partly semicrystalline, and some- 

 times nearly compact. In the last variety there are, in some 

 localities numerous indeterminable organic remains. 



2. M. Neumayr and L. Burgerstein state that the broad 

 peninsular mass in South Roumelia, below Salonica, known as 

 Chalkidike (Chalcidica), is for the most part composed of 

 micaceous and other schists, excepting its south-west portion and 

 the Athos promontory. At some places considerable beds of 

 marble are intercalated. The middle promontory of the three 

 terminating the great peninsula is called Longos, and consists of 

 gneiss, the oldest rock of the region. 



3. The Island of Cos, according to Neumayr, consists for 

 the most part of schists, marble, and Hippurite-limestone (with 

 Uudista;). The remainder is occupied by upper tertiary and 

 diluvial deposits. Of the tertiaries the lower pliocene pilu- 

 dina beds strikingly resemble, in their fauna, the analogous 

 Sclavonian deposits, and over them lie marine pliocene beds and 

 rhyolitic tufts ; and eruptive rocks, trachytic in character, are 

 also present. Being the extreme eastern member of the Cyclado- 

 Sporadic series, traversing the Egean, and being connected with 

 the neighbouring volcanic islands, Cos is well adapted to afford 

 an insight into the nature of this submarine mountain-chain, and 

 it yields an indication of the South-Egean basin being a depressed 

 area of diluvial origin. The freshwater pliocene fauna offers 

 interesting materials for the discussion of the upper tertiary fresh- 

 water deposits of the Egean region at present known, and of 

 the evolution of the Eastern Mediterranean area. A number 

 of passages have been collected by Prof. Homes from the Greek 

 Classics, mentioning "giants' bones," which may point to places 

 where remains of fossil mammals have been found. 



NOTES FROM NEW ZEALAND 

 Wild Pigs and Wekas (Ocydromus). — Early in the spring 

 of 1876 I spent several days in fern-collecting and botanising in 

 the Malvern Hills district of Canterbury. Whilst so engaged, 

 in many places I came across fresh pig-tracks and rootings, now 

 and then sighting a boar. On one open hillside, bordered with 

 fagus woods, I found three nests of that curious rail, the weka 

 {Ocydromus) ; each of the nests contained eggs. It seemed re- 

 markable that the nests should have remained unravaged by the 

 wild pigs that were constantly roaming about the neighbourhood. 

 It is highly improbable that the keen-scented swine were not 

 aware of the weka's haunts. The trail of this bird is strong, 

 readily followed by dogs ; indeed, dogs take to this pursuit with 

 so much of pleasure and relish that many good sheepdogs 



