;28 



NATURE 



[January 9, 19 13 



interactions of these substances with calcium and 

 magnesium carbonates, e.g. 



2NaCI + CaCO,=:Na,CO, + CaCI, 



2XaCl + CaCOj + CO, + H„Oir 2NaHCO; + CaCI, 



Na.SO, + CaC0,^TNa,C03 + CaSO^, 



but it is not easy to understand how such interchanges 

 could result in the production of more than a mere 

 trace of the alkali. A more probable explanation 

 assumes as the first stage a reduction of sulphate to 

 sulphide by organic matter, living or dead, with a 

 subsequent displacement of sulphuretted hydrogen by 

 carbonic acid : — 



Na,SO,-4o = Na,S, 

 Na,S + COI+ H,0 = Na„CO, + H,S, &c 

 In support of this view there are quoted statements 

 by Lunge that the springs " are full of algae," that 

 " at a distance of three feet from their origin they 

 begin to give off sulphuretted hydrogen," and that the 

 " odour becomes more intense a little further on, but 

 ceases at a greater distance." 



The Wadi Natrun deposits were probably the oldest 

 known occurrence of natural soda in the world, and 

 they constituted the principal source of supply of that 

 commodity for thousands of years. The}' are at pre- 

 sent worked by the Egyptian Salt and Soda Company, 

 who took them over, from the Society Anonyme des 

 Soudes naturelles d'Egypte, to which latter company 

 the Government had granted at the end of 1897 «* 

 concession for fifty years. The company makes caustic 

 soda and soda ash, and, in addition, extract and sell 

 both natrun (raw soda) and salt. According to the 

 customs returns the exports include 1200 tons of 

 caustic soda, value about io,oooZ., and about 800 tons 

 of natrun. But both these products are sold also for 

 use in the country, and the companv uses considerable 

 quantities of caustic soda at its own soap factory. 



The Wadi Natrun is connected with the State rail- 

 way system by means of a narrow-gauge railway 

 50 kilometres long, running from Khatatba to the 

 centre of the Wadi. T. M. L. 



.AGRICULTURE IN INDI.i. 



rHE .'Igriciiltiiral Journal of India (vol. vii., part iv.) 

 contains several articles which testify to the 

 assiduity with which various questions are being 

 investigated. Dr. C. A. Barber contributes a paper 

 on seedling canes in India, and gives a brief outline 

 of the chief phases in the cane-sugar industry and 

 the causes which led to the raising of seedling canes 

 in Java and Barbados. Simjlar work has been car- 

 ried out in India, and records are being accumulated, 

 in order to afford data for a general classification of 

 the canes of the country. Difficulty was experienced 

 in procuring sugar-cane arrows with a fair proportion 

 of anthers containing fully matured pollen; in fact, 

 the only native cane possessing this property was the 

 Cheni of Mvsore. 



Mr. C. E. Low writes on the supply of agricultural 

 cattle in India, and after giving statistical information 

 and a description of the present situation regarding 

 cattle supply, with an examination of the various 

 features involved, discusses the question of the food 

 supply in times of famine and the measures which the 

 Government is adopting to cope with various causes 

 which tend to a diminution in the number or efficiency 

 of agricultural cattle. It is interesting to note, in 

 connection with the storage of fodder as reserves for 

 seasons of famine, that " the main objection to this 

 proposal in the popular mind seems to be that the 

 possession of stored fodder tempts a hostile neighbour 

 to revenge himself by setting light to the stack." 



Messrs. E. J. Woodhouse and T. Bainbrigge 



NO. 2254, VOL. 90] 



Fletcher report the adoption of systematic hand-pick- 

 ing of the caterpillars of Agrotis ypsilon, and the use 

 of the Andres Maire moth-trap in the Mokameh Tal. 

 During the season of 191 1 upwards of 60,000 cater- 

 pillars were hand-picked, and 2000 Agrotis moths were 

 caught in November by one trap. It is estimated that 

 by the above means 6000 acres of crops were saved. 



Mr. F. M. Howlett discusses the possibility of the 

 introduction of yellow fever consequent on the open- 

 ing of the Panama Canal and the shortened route 

 from the fever-zone in the West Indies and Central 

 America. It is pointed out that, if yellow fever were 

 introduced, and Stegomyia fasciata proved to be the 

 only effective carrier, the disease would be more or 

 less confined to the coast districts and seaport towns, 

 while if 5. scutellaris also proved effective, there is no 

 reason why it should not spread infection throughout 

 the country. The distribution of the different species 

 of Stegomvia in the larger seaports is now being 

 ascertained bv means of a systematic survey. 



N.rrUR.iL SCIENCE PAPERS .-IND 

 MEMOIRS. 



IN the sixth volume of Fortschritte der naturwissen- 

 schaftlichen lorschung, Prof. \\ . Halbfass re- 

 views the recent work on the topography, hydro- 

 graphy, and geology of the lakes ol Asia, Atrica, 

 America, and Australia. Dr. A. Ruhl, in his paper 

 on a new method in geomorphology, pleads for the 

 application of the deductive method to the borderland 

 between topographical geology and geography. The 

 exposition of the peneplain theory pt Prof. Davis, as 

 well as of other points bearing on normal marine, 

 glacial, and arid cycles, is illustrated by photographs 

 and diagrams. The results of recent researches in 

 radio-activity, particularly on uranium, thorium, and 

 actinium, form the subject of a review by Prof. Otto 

 Hahn and Dr. L. Meitner. 



In the same volume the classification of functional 

 mental disorders, and the existence of fundamental 

 differences, between organic and functional psychoses, 

 are discussed by Prof. O. Bumke. The problem of 

 regeneration, in its inorganic, botanical, and zoological 

 aspects, is surveyed by Prof. D. Barfurth, who appends 

 to his memoir a selected bibliography containing 

 about 500 references. After examining the various 

 theories of regeneration, he regards that of Roux as 

 being most nearly in accord with the facts observed, 

 i.e. that, in cases where regeneration can take place, 

 disturbance of the living organism in an adult indi- 

 vidual gives rise to formative stimuli in the reserve 

 germ-plasm of the adult cells or of cells not yet fully 

 differentiated, which lead to the re-establishment of 

 the organism as a whole. Dr. W. Hausmann, in a 

 paper on optical " sensibilisators " in plants and 

 animals, concludes that several pigments which occur 

 commonly in nature are photo-biological "sensibilisa- 

 tors," which react under definite physiological and 

 pathological conditions. 



Dr. W. G. van Name (in Proc. Boston Soc. Nat. 

 Hist., vol. xxxiv., pp. 413-619, plates 43-73) gives 

 an account of the simple Ascidians of the region from 

 the Gulf of St. Lawrence to Long Island Sound. This 

 coast is not rich either in number of species of 

 Ascidians or in those presenting striking structural 

 characters. Leaving out of account all uncertain 

 forms, thirty-four species (seven of which are new) 

 are recorded. The genus Bostrichobranchus, known 

 only from the Atlantic coast of North America, is the 

 most interesting Ascidian described in this memoir. 

 Dr. van Name regards this as the most highly 

 specialised genus of Ascidians, and as having been 

 derived from the genus Eugyra. 



