4o8 



NATURE 



[August 25, 1892 



and names in unwritten languages would be rendered phoneti- 

 cally. The land surface of the globe would be represented in 

 769 sheets, and on an edition of looo copies it is estimated that 

 there would be a deficit of over ;,f 100,000 if the sheets were sold 

 at 2J. This sum would require to be subscribed by the Govern- 

 ments interested, or by private individuals. The practicability 

 of such a map is proved by the fact that Mr, Ravenstein has 

 himself produced with the aid of the Royal Geographical 

 Society 46 five-degree sheets of a map of Africa. The utility 

 of the new map is universally conceded. 



Recent Travels. — Mr. Walker Harris described an adventur- 

 ous journey through Yemen in the early part of this year, during 

 a rebellion of the Arabs against the Turks. In spite of inany 

 difficulties, including imprisonment by the Turkish authorities, 

 Mr. Harris succeeded in reaching Sanaa from Aden, and found 

 the country to be well watered, of magnificent fertility, and by 

 no means badly cultivated. 



Mr. Coutts Trotter summarized the recent advances in the 

 €xploration and organization of British New Guinea. 



Mr. H. O. Forbes described a visit to the Chatham Islands, 

 where he discovered the bones of a remarkable flightless bird, 

 identical with an extinct species also found in New Zea.land, 

 which is separated by 450 miles of deep water. The inevitable 

 inference is that a land connection must formerly have existed 

 between the two groups of islands. The importance of a care- 

 ful search for similar remains in other islands of the southern 

 hemisphere in the light of geographical distribution and specu- 

 lations as to former lands is obvious. 



Mr. W. R. D. Beckett, of the British Consular service in Siam, 

 was the first Englishman to descend the Mekong river from the 

 Eastern Laos States to Saigon, and described the various inci- 

 dents of his adventurous journey. 



Mr. C. W. Campbell, of the British Consular service in China, 

 described his journey through Northern Korea, reporting 

 favourably on the people as compared with the Chinese in their 

 treatment of strangers. 



Other Papers. — Prof. P. H. Schoute brought forward a new 

 scheme for draining the Zuyder Zee, and Mr. Yule Oldham, 

 lecturer on geography at Owens College, recalled attention to 

 the early discoveries of Cadamosto on the west of Africa in the 

 fifteenth century. 



Stib-section on Chemical Oceanography. — A joint meeting of 

 Sections B and E was held under the presidency of Mr. 

 Buchanan for the consideration of a series of papers on ocean- 

 ography. Mr. Buchanan communicated the result of some 

 observations of the density of the water at a depth of 2000 

 fathoms off the coast of South America made by Captain 

 Thomson, of the telegraph ship Silvertown. They are held to 

 demonstrate that the deep water there has come direct from the 

 Antarctic Sea. Prof. Pettersson gave a detailed and elaborate 

 paper on the hydrography of the Kattegat and Baltic, illustrated by 

 numerous special maps. Observations were made simultaneously 

 at a number of points in the Baltic and its approaches ; samples of 

 water were preserved in sealed tubes for estimation of gases, and 

 the density was in all cases measured on shore by means of 

 Sprengel's pyknometer. The excess of precipitation over 

 evaporation was found to cause an outflow of comparatively 

 fresh water and a progressive decrease in the salinity from the 

 Skagerrak inward. The fresh Baltic stream flows close round 

 the coast of Norway as it escapes into the Atlantic. An under- 

 current of salt water inward takes place, partly by reaction and 

 partly by the rising up of the deeper layers against the ridges 

 which divide the Baltic area into basins. This action is not 

 uniform, but occurs by successive impulses and pauses. The 

 physical boundary between the North Sea and the Baltic is not 

 in the Belts, but along the ridge joining Rligen and Felster. 

 The great mass of Baltic water from Riigen to the Gulf of 

 Finland is of uniform salinity ; it grows Salter toward the North 

 Sea, and freshens rapidly in the Gulf of Bothnia. In this 

 region of uniform salinity temperature appears to be the chief 

 cause of circulatory movement. By winter cooling a layer of 

 intermediate minimum temperature is usually formed, in which 

 flakes of ice may be produced that rise to the surface and con- 

 solidate there. Indications derived from observations fourteen 

 years apart point to a partial or complete stagnation of the 

 water in the deeper parts of the Baltic basin. The fresh Baltic 

 stream is felt in summer far to the north along the Atlantic 

 coast of Norway, but in winter it is greatly reduced, and com- 

 paratively warm North Sea water (4° to 6° C.) comes into the 

 iskagerrak. This influx is coincident with the commencement 



of the great herring fishery, which comes to an end when the 

 cold Baltic outflow is re-established in spring. 



Dr. Andrussoff, of St. Petersburg, summarized the results of 

 the recent Russian investigations on the Black Sea, the most 

 remarkable discovery being the fact that below the depth of 200 

 fathoms the great mass of the water is stagnant, and so highly 

 charged with sulphuretted hydrogen that all life is impossible. 



Each paper was followed by animated discussion, in which 

 Dr. John Murray, Dr. Buchan, Prof. Hartley, Dr. J. Gibson, 

 Mr. Irvine, and Dr. H. R. Mill took part. 



A 



THE AMERICAN ASSOCIATION, 

 PRESIDENT'S ADDRESS.^ 



DIVISION of science has a work of its own to do, a work 

 that well might be done for its own sake, and still more 

 must be done in payment of what is due to the other divisions. 

 Each section of our Association has its just task, and fidelity to 

 this is an obligation to all the sections. Those engaged in any 

 labour of science owe a debt to the world at large, and can be 

 called to give an account of what they are doing, and what they 

 have to do, that the truth may be shown on all sides. 



If it be in my power to make the annual address of this meet- 

 ing of any service at all to you who hear it — in your loyalty to 

 the Association — I would bring before you some account of the 

 work that is wanted in the science of chemistry. Of what the 

 chemists have done in the past the arts of industry speak more 

 plainly than the words of any address. Of what chemists may 

 do in the future it would be quite in vain that I should venture 

 to predict. But of the nature of the work that is waiting in 

 the chemical world at the present time I desire to say what I 

 can, and I desire to speak in the interests of science in general. 

 The interests of science, I am well assured, cannot be held in- 

 different to the interests of the public at large. 



It is not a small task to find out how the matter of the 

 universe is made. The task is hard, not because of the great 

 quantity in which matter exists, nor by reason of the multipli- 

 city of the kinds and compounds of matter, but rather from the 

 obscurity under which the actual composition of matter is hidden 

 from man. The physicists reach a conclusion that matter is an 

 array of molecules, little things, not so large as a millionth of a 

 millimetre in size, and the formation of these they leave to the 

 work of the chemists. The smallest objects dealt with in 

 science, their most distinct activities become known only by the 

 widest exercise of inductive reason. 



The realm of chemical action, the world within the molecules 

 of matter, the abode of the chemical atoms, is indeed a new 

 world and but little known. The speculative atoms of the 

 ancients, mere mechanical divisions, prefiguring the molecules 

 of modern science, yet gave no sign of the chemical atoms of 

 this century, nor any account of what happens in a chemical 

 change. A new field of knowledge was opened in 1774 by the 

 discovery of oxygen, and entered upon in 1804 by the publica- 

 tions of Dalton, a region more remote and more difficult of 

 access than was the unknown continent toward which Chris- 

 topher Columbus set his sails three centuries earlier. The 

 world within molecules has been open for only a hundred years. 

 The sixteenth century was not long enough for an exploration 

 of the continent of America, and the nineteenth has not been 

 long enough for the undertaking of the chemists. When four 

 centuries of search shall have been made in the world of 

 chemical formation, then science should be ready to meet a 

 congress of nations, to rejoice with the chemist upon the issue 

 of his task. 



It is well known that chemical labour has not been barren of 

 returns. The products of chemical action, numbering thou- 

 sands of thousands, have been sifted and measured and weighed. 

 If you ask what happens in a common chemical change you can 

 obtain direct answers. When coal burns in the air, how much 

 oxygen is used up, can be stated with a degree of exactness 

 true to the first decimal of mass, perhaps to the second, yet 

 questionable in the third. How much carbonic acid is made 

 can be told in weight and in volume with approaching exact- 

 ness. How much heat this chemical action is worth, how much 

 light, how much electro-motive force, what train-load of cars it 

 can carry, how long it can make certain wheels go round, — 

 for these questions chemists and physicists are ready. With 

 how many metals carbonic acid will unite, how many ethers it 

 « Address by Prof. A. B. Prescott, the retiring President, delivered at the 

 Rochester meeting of the American Association for the Advancement of 

 Science, August, 1892. 



NO. II9I, VOL. 46] 



