December i, 1910] 



NATURE 



1=^1 



discovered in 1850, 1858, 1866, 1873, 1880, 1888, and 

 1895, although it was missed in 1903. Its orbital eccen- 

 tricity is exceptionally small, and its perihelion distance 

 (i/) great. It is also remarkable as being the first comet 

 of which the periodicity was determined, by Goldschmidt, 

 directly, by calculation, without comparison with the 

 elements of earlier comets. 



A number of observations are also published, the magni- 

 tude being generally estimated as about 10. Dr. Schiller 

 recorded it at Bothkamp on November 10 as diffused, 

 having a suspicion of a tail, in p. a. 300°, and a granu- 

 lated nucleus of magnitude 98. Dr. Ristenpart, on 

 November 11, saw no tail, but an eleventh-magnitude 

 round nebulosity of i' diameter with a central condensa- 

 tion. Dr. Cerulli announces that he discovered the comet 

 on a plate taken on November 8. 



A System of Standard Wave-lengths. — No. 3, vol. 

 xxxii., of the Astrophysical Journal contains a list of 

 forty-nine secondary standard wave-lengths published under 

 the auspices of the International Union for Solar Research. 



The increased accuracy of modern research necessitated 

 the measurement and adoption of a standard system, and 

 to this end three independent observers were asked to 

 determine the wave-lengths of the forty-nine iron lines now 

 published. From the results secured for each line a mean 

 value has been adopted, and will in future be used in 

 solar work ; the wave-lengths range from A ^282-408 to 

 X 6494-993, and wave-lengths measured in this system 

 should be designated in future by using the symbol 

 "I. .A." The primary standard is the wave-length of the 

 red cadmium line adopted at a previous conference. 



In the same journal Prof. Kayser publishes standards 

 of third order of wave-length on the international system, 

 determined from the arc spectrum of iron between AA. 41 18 

 and 6494 ; he intends extending the measurements to 

 A 7900. He finds that some of the secondary standards 

 still contain errors of from 0004 to 0-005 -^- -^ com- 

 parison with Rowland's wave-lengths of the solar spectrum 

 gives differences varying irregularly between 0-15 and 

 0-22 A., but by subtracting about 0-19 A. from Rowland 

 all measurements can be reduced to the international 

 system with sufficient accuracy. Prof. Kayser tabulates 

 I about 370 wave-lengths, and gives the intensity, the prob- 



'- error, and the respective differences from Rowland 

 ' the observers who made the measurements for the 

 ^-londary standards, viz. Fabry and Buisson, Eversheim, 

 I and Pfund. 



j The Radial Velocity of Sirius. — .A most exhaustive 



i discussion of the radial velocity of Sirius is published bv 



Ht-rr W. Miinch in No. 4455 of the Asirotiomische Nach- 



■ten. Herr Miinch measured a large number of plates 



rn at Potsdam during the period 1901-10, and his 



•ough discussion takes up the whole of a double number 



the journal. It includes, inter alia, the errors intro- 



uuced by the measuring screw, by the different widths of 



1 the measured Mnes, by the possible uncertainty as to the 



Durity and wave-lengths of some of the lines, &c. Besides 



ral lines of yet unknown origin, he finds in the spec- 



;n of Sirius those due to Cr, Fe, H, Mg, Ni, Sc, Ti, 



^ V, and Zr, and, possibly. La and Mn. 



For the mean velocity of the centre of the Sirian svstem 



' rred to the sun he tabulates a series of seventeen values 



^ing from —80 (March 17, 1907) to —14-1 (April 4, 



1). the mean value being —10-3 km., with a mean 



bable error of ±0-4 km. Omitting the observations of 



6 and 1908, which gave abnormally large values, the 



.mean radial velocity becomes —9-8 km., with a mean 



! probable error of ±0-3 km. 



" -Annuaire du Bcreau des Longitudes, 1911." — The 

 Aimuaire for 19 11 published by the Bureau des Longitudes 

 contains the usual astronomical tables, ephemerides, &c., 

 : and also tables relative to metrolc^y, moneys, geography, 

 j meteorology, and statistics; this year the tables of chemical 

 and physical data are omitted, as also are matters refer- 

 |ring to the sundial, solar physics, and the minor planets. 

 I The special articles, four in number, are verv interest- 

 |ing; the first deals with the sixteenth conference of the 

 'International Geodetic .Association, which was held in 

 jLondon, and in the second M. Bigourdan publishes a great 

 di^-al of interesting information concerning the total eclipse 



NO. 2144, VOL. 85] 



of the sun which will take place on April 17, 1912, and 

 will be visible in France for a few seconds. 



M.agmtude of Nova Sagittarii, No. 2.— .A telegram 

 from Dr. Ristenpart, Santiago, announces that on 

 November 7 the magnitude of Nova Sagittarii (96.1910} 

 was 9-9 (Astronomisch^. Nachrichten, No. 4456). 



AGRICULTURAL RESEARCH IN JAPAN.^ 



THE Japanese have entered the field of agricultural 

 investigation with characteristic energy and thorough- 

 ness, and have shown a lively appreciation of the fact, 

 not alwavs realised elsewhere, that the principles under- 

 Iving an agricultural problem must first be studied before 

 the problem itself can be solved. Some of the special 

 features of Japanese agriculture present highly important 

 problems, the development of which will be awaited with 

 much interest. 



The present volume of the Journal of the College of 

 .Agriculture contains, in the two parts already published, 

 four papers, of which three deal with silkworm problems. 

 Mr. K. Toyama reports studies on the red worms occasion- 

 allv appearing among the progeny of the normal black 

 worms, and hitherto regarded in a general way as sports. 

 In 1905 he obtained some red worms, and studied their 

 behaviour on crossing. The results showed that the 

 phenomena are really Mendelian, black being dominant 

 over red ; the red worms uniformly yielded red offspring, 

 while the matings of the blacks resulted in the production 

 of one red to three blacks. Prof. C. Sasaki deals \vith 

 jaundice of the silkworm, a disease prevalent in all silk- 

 worm countries, and frequently found in Japan. The 

 worms lose their appetite, weaken, and finally die ; the 

 skin loses its firmness and becomes soft and weak, while 

 polvhedral bodies appear in the blood and various tissues. 

 Evidence is adduced that the disease is caused by a 

 streptothrix found in the blood of effected worms. The 

 polvhedral bodies may, however, arise from other causes 

 such as a small dose of formalin, interruption of respira- 

 tion, or attacks of maggots, and are probably to be ascribed 

 to the degeneration of the contents of the nucleus. The 

 same author has also solved an interesting problem that 

 has hitherto been overlooked. Silk fishing lines, commonly 

 known as " Tegusu," are largely employed by the Japanese 

 fishermen, but no one has up to the present found out 

 anv more about their origin than that they are imported 

 from southern China. The Chinese writers say that some 

 wild silkworms found in A'oko on the leaves of camphor 

 trees and Foushu (Liquidambar formosana) are the source. 

 In April, when the worms are mature, they are dipped 

 in vinegar, and then filaments 7 or 8 feet long and golden- 

 vellow in colour are taken from their bodies. Prof. 

 Sasaki made a journey in southern China, found the 

 worm, and determined it as the larva of Saturnia 

 pyretorum, Westwood. He has also introduced it into 

 Formosa. 



Mr. S. Kusano has a paper on chemotactic and similar 

 reactions of the swarm spores of myxomycetes, ^thalium, 

 Stemonitis and Comatricha being investigated. In 

 general, these organisms feed mostly on rotten wood or 

 leaves, and there is evidence that they can digest bacteria. 

 It appears also that they can themselves be devoured by 

 infusoria. \\'ood attacked bv them was found to be acid. 

 The swarm spores showed marked chemotaxis, being 

 attracte4 by acids, repelled by alkalis, and unaffected by 

 neutral, non-poisonous substances. A consideration of the 

 phenomena from the dissociation hypothesis indicates that 

 the H- and OH-ions are in all cases the stimulating com- 

 ponents, the OH being much the more effective, and active 

 even at a dilution of N/ 10,000. The attraction of the 

 H-ion reaches a maximum at N/600; in higher concentra- 

 tion the acid repels and injures the organism. H-ions 

 act beneficially in several ways ; they promote germina- 

 tion of the spores, and then attract them to the place 

 where food material occurs. -An interesting physiological 

 point was noticed. The spores germinate much more 

 readily in contact with moist air than when thrown on 

 to water ; in the latter case they do not appear to be 

 wetted very quickly. 



1 J' umal of t><e College of Agriculture, Imperial University of Tokyo, 

 vol. ii. , Nos. I and 2. 



