April 26, 1917] 



NATURE 



171 



Department of Agriculture in India (vol. iv., No. 6). 

 This paper is especially noteworthy for a discussion 

 of the effect on the insects of inert gases and varia- 

 tions in temperature and moisture, as connected with 

 the respiratory function. Hydrogen kills beetles more 

 rapidly than nitrogen, and nitrogen than carbon 

 dioxide; an increase in temperature causes a shorten- 

 ing of the lethal period. As to the effect of moisture, 

 Calandra and Rhizopertha are destroyed by desicca- 

 tion, but Attagenus "prefers dry conditions lo moist 

 ones.". 



It is thirty years since Profs. Tracy and Goff estab- 

 lished in the United States the value of tarred paper 

 discs in preventing the access to cabbage-roots of the 

 cabbage-fiy {Phorhia brassicae) for the purpose of 

 egg-laying. Although the maggots of this insect are 

 among the most destructive farm and garden pests 

 known to us in these islands, British and Irish cul- 

 tivators who have heard of the American preventive 

 measure have usually derided it. They may perhaps 

 be convinced by the " Report on a Trial of Tarred Felt 

 Discs for Protecting Cabbages and Cauliflowers," 

 which Mr. J. T. Wadsworth publishes in the Annals 

 of Applied Biology (vol. iii., 1917, pp. 82-92). From 

 his research, carried out for the Manchester University 

 Department of Agricultural Entomology, it appears 

 that 63 per cent, of unprotected cauliflowers and 

 13-2 per cent, of unprotected cabbages are lost, as 

 against 5-1 per cent, and 0-2 per cent, respectively of 

 those plants provided with cards. We understand 

 that a local merchant is now putting effective discs on 

 the market. 



The grading for stock-feeding purposes of the 

 various "offals" produced in the milling of wjieat 

 has always been a source of much confusion to the 

 farmer and his advisers. It is a common experience 

 for otfals sold under a particular name in one district 

 to differ widely, both in general character and in 

 chemical composition, from materials sold under the 

 same names in other districts. The confusion is 

 mainly due to local variations in milling practice, and 

 little success has attended past efforts at standardisa- 

 tion. A substantial advance should now be possible, 

 however, in the light of observations made by Messrs. 

 T. B. Wood and R. H. Adie, which are recorded in 

 the March issue of the Journal of the Board of Agri- 

 culture. Their results indicate that, excluding the ex- 

 treme fractions, flour and bran, milling offals may be 

 classified into three "pure grades" (fine middlings, 

 coarse middlings, and pollards) coming from the mills 

 where the intermediate offals are most completely 

 separated, and three "mixed grades" coming_^ from 

 mills where the offals are not so completely divided. 

 The number of samples examined by Messrs. Wood 

 and Aciie, though not large enough to establish 

 standard compositions for the "pure grades," was 

 sufficient to demonstrate that these grades are charac- 

 terised, not only by a limited range in the size of 

 their particles, but by a definite chemical composition. 

 It is suggested that millers should adopt a uniform 

 system of grading and naming their offals, and a 

 simple method of achieving the latter object, whilst 

 retaining the local trade names, is indicated. 



Messrs. Stanford have just issued a new and en- 

 larged edition of No. 17 of their large-scale war maps ; 

 it includes Tournai, Cambrai, and the environs of 

 St. Quentin on the east, and shows* the defensive line 

 held by the enemy from the date of the Marne defeat 

 until the opening of the Somme battle; and it also 

 shows the line to which the enemy had been driven 

 by April 17 during the battle of Arras. An interesting 

 feature of this series is the diagrammatic way in 



NO. 2478, VOL. 99] 



which the levels of the land are shown; tints of 

 brown colour distinguish the land lymg oetween sea- 

 level and 125 ft. above, between 125 ft. and 250 ft., 

 250 ft. and 500 ft., and 500 ft. and 1000 ft. above sea- 

 level ; this gives the map-reader an excelk-nt idea of 

 the lie of the country'. 



In a Bulletin issued by the Department of Chemistry, 

 Adelaide, the director. Dr. Hargreaves, discusses the 

 practicability of manufacturing cream of tartar in 

 South Australia. Grapes, the source of tartar, are 

 largely grown in the countrj-, but at present all the 

 tartaric acid and most of the cream of tartar used in 

 South Australia are imported from Europe. Expjeri- 

 ments showed that a quite satisfactory process was 

 available. The wine lees receive a preiiminary roast- 

 ing at a temperature of 120° to 150^* C, which is high 

 enough to decompose the albuminous and organic 

 colouring matters without injuring the cream of tartar; 

 this much facilitates filtration. The cream of tartar 

 is tfien extracted with hot water, filtered, and crystal- 

 lised out. There is not a projnising field for a large 

 industry, because the total possible production, it is 

 calculated, would not be sufficient to supply the needs 

 of the country. Nevertheless, the available tartar 

 should not be allowed to go to waste as at present, 

 and a start has been made with the manufacture. 



We learn from the Geographical Journal for April 

 (vol. xlix.. No. 4) that, at the request of the -As- 

 tronomer Royal, the Royal Geographical Society is 

 collecting information about possible observing stations 

 for the total solar eclipse on May 29, 19 19. The 

 eclipse passes over the Amazon basin, the Atlantic 

 Ocean, and the Congo basin to Tanganyika. Possible 

 stations are suggested in the State of Ceard in Brazil, 

 the Island of Principe, the neighbourhood of Libre- 

 ville in the French Congo, and on the western escarp- 

 ment of Tanganyika. Between Libreville and Tan- 

 ganyika the forest conditions preclude tfie possibility 

 of a station The essential conditions for an eclipse 

 camp are the good chance of clear weather; reason- 

 able accessibility, with means of transport for heavy 

 instruments ; a\'ailable local labour and materials for 

 the construction of huts and the foundations for in- 

 struments; and a good supply of pure water for 

 photography. The society will be grateful to any 

 correspondents who may be so good as to send advice 

 in these matters. 



In fulfilment of the international scheme of which 

 it is the centre, the Meteorological Institute of th« 

 Netherlands has recently issued copies of a number 

 of records of magTietic disturbance obtained during 

 19 14 and 19 1 5 at De Bilt Observatorj'. In all, twenty- 

 three magnetic storms are dealt with — twelve from 

 1914 and eleven from 1915. In each case the record 

 includes thirty consecutive hours, declination, hori- 

 zontal-force, and vertical-force traces being shown on 

 the same sheet, referred to a common base or time 

 line. The base-line values and the scale values of the 

 ordinates are marked in each case. The disturbances 

 selected afford excellent examples of "sudden com- 

 mencements," "bays," slow and rapid oscillations, 

 and isolated tooth-like protuberances on the curves. 

 The tendency in the vertical force to be above its 

 normal value during late afternoon hours in times of 

 disturbance is conspicuous in the majority of instances. 

 One or two of the storms selected for 1915 were of 

 considerable size, especially that of June 17-18. The 

 sensitiveness of the horizontal-force and vertical-force 

 magnetographs is unusually high at De Bilt. This 

 enables details of moderate movements to be more 

 readily recognised, but increases the risk of loss of 

 trace during large movements, and makes it more 



