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NA TURE 



\_July 24, 1 1 



different at different places ; and the fact that absorptio- 

 metry exchange had not gone far enough to reproduce 

 equilibrium would account for the few cases in which the 

 dissolved gases exceeded the amount calculated. The 

 interpretation of his results seemed unsatisfactory to Prof. 

 Dittmar. He says (p. 182) : — 



" I am sorry to have to confess that I have not been as 

 successful as I should have wished in drawing general 

 conclusions from my numbers, and if I here reproduce 

 my endeavours in this direction, I do so chiefly in the 

 hope that some other person, having more experience 

 than I in dealing with statistics, may take up the problem 

 after me, and perhaps be able to extract the latent propo- 

 sitions which are therein concealed. In the tables which 

 I propose to give, he will find all the data arranged in the 

 most convenient form, so that all he needs is at hand." 



The problem of the dissolved gases is very difficult 

 when deep waters are considered. The method pursued 

 by Dittmar was to find the amount of nitrogen absorbed, 

 and to calculate the temperature at which that quantity 

 would be taken up by water at the surface ; then to find 

 the corresponding amount of oxygen, and compare that 

 with what was found by experiment. It is evident that if 

 the ocean were stagnant in any part the processes of oxi- 

 dation always going on would tend to reduce the amount 

 of absorbed oxygen finally to nothing, while the amount 

 of dissolved nitrogen would be unaltered, unless it were 

 slightly increased by the decomposition of animal matter. 

 In many cases the oxygen deficit was found to assume very 

 large dimensions, though oxygen was never wholly absent 

 from the dissolved gases. 



Part I. of the volume closes with a summary of the 

 chemical work, a note by Mr. Buchanan on the deter- 

 mination of carbonic acid, and an appendix describing 

 some analytical methods. The summary contains a num- 

 ber of valuable suggestions for future work. These 

 are divided under two heads, the first comprising such 

 observations of water density and rough volumetric de- 

 terminations of the alkalinity as can be carried on by 

 any intelligent seafaring man after a little instruction. 

 The second head includes work requiring the services 

 of a skilled chemist for its accomplishment. It embraces 

 further researches on the composition of ocean salts by 

 determining with the utmost precision the amounts of the 

 principal constituents for one particular station in the 

 ocean, water from which could be collected in large quan- 

 tity at various seasons ; then it could be compared with 

 water taken at various seasons from a widely distant sta- 

 tion, and thus the interesting question as to whether there 

 is any difference in the proportion of the salts in different 

 oceans could be settled. The minor constituents should 

 also be estimated if possible, and very particular attention 

 ought to be paid to alkalinity and carbonic acid deter- 

 minations in freshly drawn simples. Prof. Dittmar con- 

 cludes with this significant suggestion: — 



" Meanwhile the best thing that could be done in regard 

 to all the analytical problems referred to would be to work 

 many times on samples of the same kind of water, with 

 a view of improving on the methods and ascertaining 

 the extent to which that one water fluctuates in its 

 composition." 



The only way in which this can be done properly is in 

 a laboratory on shore situated within easy reach of an 

 abundant supply of sea water, and the support of such 

 laboratories ought to be a leading feature in the marine 

 stations several of which, it is to be hoped, will soon be 

 in working order on our coasts. A beginning has already 

 been made at the Scottish Marine Station at Granton, 

 where the special chemical problem under investigation is 

 estuary water. The Challenger results may be regarded 

 as final, for the present at least, for ocean water proper, 

 and the results of the German and Norwegian North 

 Atlantic Expeditions have put the waters of partially in- 

 closed seas on a permanent basis ; but the study of 



estuary water has been almost neglected. This is the 

 more regrettable because of the practical importance of a 

 correct knowledge of the conditions of the water of an 

 estuary, on account of its bearing on the migration of 

 fishes into firths and up tidal rivers. 



There could be no better field than the estuaries of the 

 British coast for carrying out Prof. Dittmar's suggestion 

 of continuous work on one kind of sea water with a view 

 to the perfecting of analytical methods ; and the perfecting 

 of analytical methods, important though it be, may safely 

 be predicted to be one of the least valuable results of such 

 researches. Hugh Robert Mill 



ORNITHOLOGICAL NOTES 



SEVERAL new magazines have made their appearance 

 during the present year, the most important of them 

 being undoubtedly the Auk, which is the name proposed 

 for the journal of the American Ornithologists' Union, 

 and which is to represent in America our old friend the 

 Ibis of this country. The Auk is in fact a continuation 

 of the Bulletin of the Nuttall Ornithological Club, and 

 the general style of the work is the same. The papers 

 seem to be interesting enough, but what strikes us as 

 being decidedly above the average is the quality of the 

 reviewing, which is developing into an art with our 

 American brethren. Mr. Cory describes some new 

 species of birds from Santo Domingo, the plate which 

 accompanies his paper being scarcely up to the level of 

 American illustration. Mr. Barrows continues his useful 

 papers on the birds of Uruguay, and Prof. Merriam criti- 

 cises Dr. Coues' " Check List," calling forth a sharp 

 rejoinder from the last-named author in an article called 

 " Ornithophilologicalities." In No. 2 many of the above- 

 named papers are further continued along with others by 

 Dr. Stejneger, who advocates some startling changes in 

 ornithological nomenclature, and who also writes a useful 

 paper on the genus Acanthis. Altogether, although the 

 American ornithologists have elected to name their quar- 

 terly journal after a bird whose powers of flight were small, 

 the excellence of the two numbers which have appeared 

 reminds us of the perfection of that bird's powers of swim- 

 ming and diving, so that they have taken as their symbol 

 a species of lusty prowess which argues well for a con- 

 tinuation of the life and enterprise which is visible in the 

 new magazine. We do not forget also that the Auk 

 was a species common to Great Britain and North Ame- 

 rica, and therefore the very title is suggestive of a bond 

 of union between British and American ornithologists 

 which is certain to be strengthened with each succeeding 

 year. 



We have also received No. 1 of the Bulletin of the 

 Ridgway Ornithological Club, which has been started in 

 Chicago, and is named after Mr. Robert Ridgway, the 

 well-known Curator of the Ornithological Department in 

 the United States National Museum. The secretary of 

 the new club is Mr. H. K. Coale, who is well known 

 as a zealous and painstaking ornithologist, and under 

 whose auspices there is doubtless a useful future before 

 the infant society which he represents. The first number 

 of the Bulltin contains only a single paper by Messrs. 

 W.W.Cook and Otto Widmann, entitled " Bird Migration 

 in the Mississippi Valley.'' 



Mr. J. H. Gurney has just issued a " List of the 

 Diurnal Birds of Prey, with References and Annotations ; 

 also a Record of Specimens preserved in the Norfolk 

 and Norwich Museum," consisting of 187 pages. The 

 raison d'etre of this most useful work consisted in the 

 publication of the first volume of the " Catalogue 

 of Birds in the British Museum," by Mr. R. Bowdler 

 Sharpe. The Norwich Museum, as is well known, 

 contains one of the finest series of birds of prey in the 

 world, and it will always be an imperishable monu- 

 ment to that true and self-sacrificing naturalist, Mr. J. H. 



