March iq, 1903] 



NA TURE 



465 



means of half-tint blocks, for the most part of a very 

 clear and satisfactory character, of photographs taken 

 by the author. Each plate is accompanied by a letter- 

 press description, calling- attention to the principal 

 phenomena which are illustrated in the plate. In a short 

 introduction upon " Photographic Methods," the 

 author gives a number of valuable hints, which cannot 

 fail to be of service to every geologist who wishes to 

 go abroad armed with the camera. Dr. Tempest 

 Anderson's remarks on the lenses to be employed, on 

 the importance of the use of a firm stand, and on the 

 relative advantage of plates and films, should be 

 read by everyone desirous of doing good work in this 

 direction. 



Of the photographs reproduced in the 105 plates of 

 this volume, seventeen are taken from Vesuvius and the 

 surrounding country, two from Etna, eight from the 

 Lipari Islands, eleven from the Auvergne and Central 



••■-■'■Fig jr.. — A Gaj (pronoun Gejw), Reykjanes Peninsula, Iceland 



France, eight from the Canaries, thirty-two from Ice- 

 land, five from the Eifel and Central Germany, eight 

 from the Yellowstone Park and other parts of the 

 Western Territories of North America, ten from various 

 ancient volcanic districts in the British Isles, and four 

 from the West Indies. 



Most of the pictures are wider than the page of 

 Nature, but the one here reproduced will give a good 

 idea of their general character. Those who have seen 

 reproductions as lantern-slides of these photographs 

 thrown in an enlarged form upon a screen can 

 testify to their excellence and value. The fact that 

 in many cases — notably in Iceland and the West 

 Indies — the work has had to be carried on under most 

 unfavourable conditions, while it increases our ad- 

 miration for the skill and perseverance of the author, 

 cannot but greatly enhance the value of the results 

 obtained. The author of this work is to be con- 

 gratulated upon having discovered a field of work in 

 which he is able to make such valuable contributions to 

 science. J. YV. J. 



NO. J 742, VOL. 67] 



THE AFTERMATH OF THE PARIS 

 EXHIBITION. 



THE size and importance of the Paris Exhibition 

 *■ of 1900 is beginning to be appreciated in its true 

 significance. Many who visited the exhibition in a 

 casual way were greatly impressed with its vastnest 

 and came away with the feeling that the exhibition 

 was a marvellous illustration of the Frenchman's power 

 of organisation ; but that, owing to its very immensity, 

 it lost much of its practical value. The aftermath of 

 the exhibition is still with us, and we begin to see — 

 from the number of special reports upon the different 

 departments — that although not a financial success, the 

 exhibition has left its mark upon commerce and science 

 in a way that bids fair to rival, in its economic results, 

 the immense advantages that accrued to this country 

 from the Great Exhibition of 1851, and justly to warrant 



the enormous labour put 

 forth in its inception and 

 organisation. 



In the Revue ginerale 

 des Sciences (November, 

 1902) Prof. A. Haller, of 

 the Paris University,, 

 contributes the first part 

 of a most interesting and 

 suggestive article upon 

 the " Chemical and 

 Pharmaceutical Indus- 

 tries " at the Paris Ex- 

 hibition. He commences 

 with a reference to the 

 retrospec tive stand, 

 where apparatus and 

 substances of historical 

 interest were exhibited. 

 Amongst these exhibits 

 were specimens of alu- 

 minium as prepared by 

 YVohler, sulphuric anhy- 

 dride by Winckler, the 

 first specimen of mag- 

 nesium which was pre- 

 pared electrolytically by 

 Bunsen, and many other 

 products and apparatus 

 of historical interest. He 

 then goes on to refer to- 

 artificial substances such 

 as ultramarine, syntheti- 

 cal perfumes, pharma- 

 ceutical preparations and a very complete collection of 

 coal-tar dyes. 



The article is mainly devoted to the German chemical 

 industries, and by far the most interesting paragraphs 

 are those in which Prof. Haller reviews the great 

 advance in German science, and endeavours to assign 

 a reason for this phenomenal development. En 

 passant, he regrets that Great Britain did not see her 

 way to send apparatus and specimens of historical 

 interest, which she, who can boast of the great names 

 of Priestley, Cavendish, Davy and Faraday, might so- 

 easily have done. 



The recent trade depression in Germany has attracted 

 considerable attention, but although many branches 

 of industry have been passing through a period of great 

 difficulty, and the total German exports for 1901 

 showed a decrease of 240 million marks, the exports of 

 the chemical trade showed an increase of 10 million 

 marks. Prof. Haller attributes much of the success, 

 of the Germans in the chemical trade to the manage- 

 ment and to the employment of men of high scientific 



