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NATURE 



[June 3, 1920 



were the French botanist, Philibert Commerson, who 

 was surgeon and naturalist to Bougainville's expedi- 

 tion (1767-68), and Sir Joseph Banks, who with 

 Daniel Solander accompanied Cook on his first voyage 

 round the world (1768-71), and brought home exten- 

 sive botanical collections from the southern hemi- 

 sphere. The collections of the Spanish naturalists, 

 Ruiz and Pavon, at the close of the eighteenth cen- 

 tury were the foundation of an important work on the 

 flora of Peru and Chile. John Miers spent several 

 years in La Plata and Chile, accumulated a large 

 herbarium (now at the British Museum), and pub- 

 lished monographs of various South American families 

 of plants. Charles Darwin visited Argentina, Chile, 

 and Patagonia, and Sir Joseph Hooker in his work 

 on the Antarctic flora contributed largely to our know- 

 ledge of the botany of the Magellanic area. Valuable 

 botanical exploration was also carried out by collectors 

 sent out by the firm of Veitch — William Lobb and 

 Richard Pearce. The Philippis, father and son, 

 worked for nearly fifty years, collecting and publishing 

 extensively on the flora of Chile. These are a few 

 only of the long list of botanists and collectors 

 chronicled by Mr. Turrill, who, in conclusion, points 

 out that there is still scope for botanical exploration, 

 especially on the Argentine side of the Andes. 



In view of the present high prices of sugar, con- 

 siderable interest is being taken in the question of 

 the possibilities of sugar-beet production in England. 

 The Weekly Service for April 3 from the Ministry of 

 Agriculture and Fisheries contains some useful in- 

 formation on this point. Even apart from the pro- 

 duction of sugar, sugar-beet is a useful crop to grow. 

 The food for stock would not be materially reduced 

 by substituting sugar-beet for roots in the rotation, 

 while both leaves and by-products make excellent 

 cattle food. To ensure good crops the land has to be 

 very thoroughly cultivated — a process which reacts 

 favourably on subsequent crops — and there is the 

 further advantage that the crop gives a direct 

 monetary return. Extensive trials were made before 

 the war, and these showed that many parts of the 

 countrv are suitable for large-scale production of 

 sugar-beet for the manufacture of sugar ; but it must 

 be clearly understood that, owing to the bulky nature 

 of the crop and the consequent difficulties of transport, 

 it is advisable to grow beet for sugar production only 

 when the land is within reasonable transport distance 

 of a factory. 



Students of the continental deposits of the Old 

 Red Sandstone and Triassic days may well take note 

 of the illustrative matter provided in South Africa 

 and described concisely by Mr. Wm. Torrance 

 ("Observations on Soil Erosion," Union of S. Africa, 

 Dept. of Agric, Bull. 4, 1919, price 3d.). The 

 numerous photographs are small ; but some, like that 

 of the infilled ylei at Grootfontein, are highly suj^- 

 ge stive. 



Among the many well-produced Water-Supply 

 Papers of the United States Geological Survey which 

 have reached us are several dealing particularly with 

 the surface water-supply for the year ending Septem- 

 ber 30, iqi6. Work of this nature was begun many 

 NO. 2640, VOL. 105] 



years ago in connection with studies of irrigation 

 problems in arid areas, but a particular effort was 

 made in 19 15-16 to obtain synchronous observations 

 of the flow of streams. The data supplied for each 

 gauging station in the area covered by each report 

 include a description of the station and tables giving 

 the daily, monthly, and yearly discharge. Illustra- 

 tions of current meters and water-stage recorders are 

 given. 



The reclamation of salt soils is an important agri- 

 cultural problem in India. Without a soil survey it 

 is impossible to say what area is affected, but in 

 Sind, and to a less extent in the Punjab and the 

 United Provinces, it must be considerable. These so- 

 called alkali lands are either uncultivable or injurious 

 to the growth of crops. "Notes on Practical Salt- 

 Land Reclamation " is the title of a paper published 

 as Bulletin No. 91 by the Agricultural Research Insti- 

 tute, Pusa. Mr. G. S. Henderson, the author of the 

 paper, examines the methods employed in Egypt in 

 the reclamation of Lake Aboukir in the Nile delta, 

 and draws some useful conclusions as to comparable 

 work in India. He insists that the Egyptian method 

 of washing the salt into the subsoil is the only effec- 

 tive way of dealing with the problem. Periodical 

 surface washing is unsatisfactory. It is pointed out, 

 however, that until the Indus barrage is completed 

 there is not enough water in Sind for this purpose, 

 all the available supply being required for irrigation. 

 The Germans during the war, when materials were 

 short, gave a certain amount of attention to the 

 utilisation of blast-furnace slags, and succeeded in 

 obtaining a satisfactory cement after many experi- 

 ments. A new use for slag is foreshadowed in an 

 article in Stahl und Eisen (March 4), viz. for the 

 manufacture of light bricks for building purposes. By 

 passing molten slag horizontally through water, the 

 steam generated blows out or extrudes the slag jet, 

 and forms what the Germans term "spume" slag or 

 artificial pumice-stone. This material has been 

 patented under the name of " thermosite," owing to 

 its excellent heat-insulating properties. The patentee 

 has also invented a press for pressing bricks formed 

 of small pieces of this artificial pumice and a mixture 

 of slag, sand, and slaked lime which is used as a 

 binder. The bricks thus formed are strong and light, 

 and resemble in their properties the alluvial (tuff) 

 stone obtained in the neighbourhood of Andernach. 

 As, in addition, they can be pressed to large dimen- 

 sions, less mortar will be required in building opera- 

 tions. The German authorities have approved of the 

 new tvpe of brick for house-building. 



In the Revue gdndrale des Sciences for April 

 M. Florentin gives an interesting account of the 

 French experience of German gas warfare, with 

 full chronological details of its development and 

 an account of the properties of the substances 

 used, as well as of their mode of manufac- 

 ture. The section of the French Gas Service 

 under M. Kling, director of the Paris Municipal 

 Laboratory, -examined about 2400 samples of material, 

 of which half were shells and projectiles, . M. 

 Grignard devoting himself specially to the detection 



