74 



NATURE 



\_Nov, 25, 1875 



which lead to the polar sea — between Greenland and 

 Spitzbergen, between Spitzbergen and Novaya Zemlya, 

 and through Behring Strait — and which have a phy- 

 sical connection, which is shown very distinctly in the 

 isothermal curves. In this undertaking the co-opera- 

 tion of all States having an interest in these researches 

 stiould be sought. Through the simultaneous action of 

 different States a circle of observing points would be 

 formed, which would sub-divide a common work having 

 the same end in view, so that the combined labour of 

 several nations would entail less sacrifice to each than has 

 hitherto been the case. The Commission also recom- 

 mends the above principles for the guidance of other 

 nations, and thus an international alliance might be 

 formed through which the highest scientific results would 

 be attained. The Commission points out that one imme- 

 diate result of the Second German Expedition is that the 

 region between the west coast of Greenland and the east 

 coast of Spitzbergen would be a suitable field for German 

 research. As we have already stated (Nature, vol. xiii., 

 p. 33), they recommend a principal station to be estab- 

 lished on the east coast of Greenland, with secondary 

 stations on Jan Mayen Island and the west coast of 

 Spitzbergen. 



In the region indicated for observation, which can easily 

 be reached from Central Europe, and whose exploration 

 has for European States the greatest scientific and 

 practical interest, German explorers have made a happy 

 commencement, and established a claim for Germany to 

 continue the work thus begun. The Commission urge 

 Germany to set about at once fitting out an expedition 

 for the occupation of the above region. They believe that 

 if diligent preparations were made, the expedition might 

 be ready to start in 1877. Finally, they recommend the 

 appointment of a Scientific Commission to draw up full 

 instructions for the guidance of the expedition in all de 

 partments. 



THE FAUNA OF THE CASPIAN SEA 



OSCAR GRIMM has given in Von Siebold and Kol- 

 liker's Zeitschrift a brief account of his exploring 

 expedition to the Caspian Sea last year, which will make 

 naturalists look expectantly for the completion of his 

 descriptions. The character of the fauna of the Caspian 

 has interest for the evolutionist in natural history, as well 

 as for the geologist. It will afford evidence not only of 

 modification of animal life, but also of successions of 

 change in physical geography. Two months were spent 

 at Baku, and one month on board a steamboat in dredging 

 from Baku to Krassnowadsk, thence to the Balchan Bay 

 on the east coast, by the island of Tscheleki, southwards 

 to Astrabad, and thence by Enzili and Lenkoran to Baku. 

 Dredging was carried on up to a depth of 150 fathoms, 

 and an enormous quantity of specimens was obtained, 

 including six new fishes (Gobius and Benthophilus), 

 twenty species of MoUusca, including four species of 

 Cardium, four of Adacna, and three of Dreyssena ; thirty- 

 five species of Crustacea, principally colossal forms of'^ 

 Gammarldae ; and twenty species of Vermes. The eastern 

 coast adjoining the sandy steppes was almost destitute of 

 marine life, owing to the quantity of sand blown into the 

 sea. The western part of the sea gives depths of 517 

 fathoms, and has a very abundant fauna. At one haul of 

 the dredge in 108 fathoms, not far from Baku, there were | 

 taken 350 specimens of Gammaridse, \^o Idotliea entomoii, 

 fifty colossal Mysis, six species of fishes, and many large i 

 MoUusca. i 



One hundred and twenty species in all were taken, of 

 which eighty are new to science. Many more might be 

 expected to reward dredgings in the deeper parts of the 

 sea. Those already known fall into two classes : (i) those 

 derived from still existing or already extinct species, or 

 but slightly differing from species living in the neares> 



Y 



seas ; and (2) those which are identical with those of other 

 seas. The latter are spejies possessing special tenacity 

 of life, such as Sabellides octocirrata, Mysis relicta, and 

 Idothea entomon. 



Relationship is shown between the Caspian fauna and 

 the faunas of the Aral and Black Seas, and the Northern 

 Ocean. But the connection with the latter is more recent 

 than with the Black Sea, for Phoca, Corei^onus leucichthys, 

 and other forms, not existing in the Black Sea, are 

 common to the Northern Ocean and the Caspian. The 

 geographical changes which Dr. Grimm conceives to have 

 brought about these results will be batter understood, and 

 their probability may be more easily criticised, when the 

 complete account of the Caspian Fauna is published. 



NEW FORM OF^TUBE FOR OBSERVING THE 

 SPECTRA OF SOLUTIONS* 



V\7'E have the honour of presenting to the Academy an 

 _ * ^ eminently useful spectro-electric tube ; t it realises, 

 in fact, a certain number of advantages, which are as 

 follows : — 



I. Constancy of spark permitting prolonged observa- 

 tion of spectra. 2. Suppression of the 

 meniscus, and consequently of the ab- 

 sorption which it produces by partly 

 concealing the spark. 3. Electrodes 

 enclosed in a special tube, which pre- 

 serves the solution from contact with 

 impurities. 4. Possibility of collecting 

 entirely the substance examined. 5. 

 Possibility of arranging a series of 

 spectroscopic tubes, enclosing solutions 

 of the various bodies, thus permit- 

 ting rapid demonstrations and com- 

 parisons. 



The closed tube A of eleven 'centi- 

 metres in height, and \\ centimetres 

 in diameter, is traversed by a lower 

 platinum electrode fj in the mouth 

 of A is fixed a cork stopper c, pierced 

 by an orifice through which passes a 

 capillary tube B. B is traversed by a 

 platinum wire c d, terminated at the 

 upper end by a ring, and at the lower 

 end by a point d^ opposite f. d and/ 

 are the electrodes. The important part 

 of the apparatus is a small capillary 

 tube, slightly conical, one centimetre 

 in height, moveable, and which covers 

 the lower electrode /, topping it by \ 

 millimetre. 



To work the apparatus, pour into 

 the tube A the solution to be- exa- 

 mined, taking care that the electrode/ 

 and the tube D are only immersed to 

 half their height. Let a (5 be the level 

 of the liquid ; capillary force deter 



- - A, Tube into which the 



mmes the ascent as far as the point HquiJ to be analysed is 

 D, on which is formed an immovable p""''-.'^ J*.' , ^*'^'i'-'IX 



,' T_-i. -11 .v^v, (ube in which is tixed 



drop wnicii is vaporised when an in- the platinum wire cd, 

 duction current is put on by c and / ",**'-^ j^o""™-^ '^'= "Pi^ 

 The observations may then continue a stoppe°r ciosing'^'theVube 

 very long time without intermission, a ; it supports b, and 

 allowing the spectra to be observed and ^1[™'{f,j|e &,„.'"'»'! 

 drawn with the greatest ease. Small capillary tubs! 



This very simple apparatus has M'gh'iy conical, covw- ; 



3 J i- • ,1 ing the lower electrode 



rendered us so great service in the y: ^ ^, Upper electrode. ; 

 course of our investigations, that we /. Lower electrode. « 3, 

 cannot too strongly recommend its Level of hqaid. 

 use to chemists engaged in spectral analysis. Never- 



* Paper read at the Paris Academy of Sciences, Oet. 26, by MM. 

 Delachanal and Mermet. Comptes Reiidus, t. Ixxxi. No. 17, p. 726. 



t See the description of the original apparatus in the " Annales de Chitnie 

 €t de Physique," 5* series, t. iii., 1874. 



