July 13, 1911] 



NATURE 



55 



cultural Society (vol. xxxvi., part 3). Calcium cyanamide 

 or nitrolim and nitrate of lime are both products manu- 

 factured at a high electrical pressure and compete indi- 

 vidually with the other two fertilisers tested. The results 

 obtained with turnip crops indicate that the first two are 

 of about equal value, but are slower in their influence 

 than the last two. Nitrate of lime suffers from hygroscopic 

 defects, and provides weight for weight rather less nitrogen 

 than nitrate of soda. Calcium cyanamide also presents 

 physical difficulties which have been obviated by the 

 production of a hydrated form. 



The account communicated by Mr. T. G. B. Osborn in 

 The Annals of Botany (vol. xxv., No. qS) of the 

 organism, Spongospora subterranca, producing " corky " 

 or " powdery scab " of potatoes, is interesting not only 

 for its economic aspect, but also for the cytological results 

 recorded. In the earliest stage, the organism was 

 observed as a uninucleate amoeba in the meristematic 

 potato cells. The amoeba 1 divide to provide units for the 

 invasion of new cells, as also to form several individuals 

 in each potato cell. Eventually the various amceba? in a 

 cell unite to form a Plasmodium. Later on nuclei become 

 very apparent in the plasmodia before fusion occurs in 

 pairs (karyogamy) ; two karvokinetic divisions ensue, after 

 which the protoplasm round each nucleus rounds off into 

 a uninucleate spore. The author concludes that Spongo- 

 spora is a member of the Plasmodiophoracea?, which group 

 has many points of relationship to the Mycetozoa, differing 

 chiefly in the parasitic habit, the method of division of 

 the vegetative nuclei, and by the less constant presence of 

 a flagellum on spore germination. 



Mr. R. Corless contributes to Symons's Meteorological 

 Magazine for June a useful article on the distribution of 

 rain in a barometric depression. It is known that the 

 est rain usually falls on the left side of the path of 

 the centre of a depression, irrespectively of the direction 

 of its motion. The reason for this is shown by a diagram 

 and a simple formula. For the sake of argument, the 

 author considers a depression in which the wind at some 

 altitude is blowing tangentially to the isobars, and for 

 the immediate purpose all that is required is that when 

 the path of the air is straight the relation vd = constant 

 holds good between v, the wind velocity, and d, the distance 

 between the consecutive isobars. When the path is curved 

 cvclonically, the value of v as determined from this equa- 

 tion is theoretically too large ; the error increases with 

 increasing curvature, and the maximum curvature is shown 

 to be on the left side of the path of the centre. The air 

 has no alternative but to rise, and an ascending current of 

 air is admittedly a cause of rain ; it is in this region (the 

 li It front quadrant of the depression) that heavy falls of 

 rain actually occur. Of course, rain falls in other parts, 

 but its origin may be quite different from that here 

 suggested. 



Under the title " La Temperatura in Italia," the Italian 

 Central Meteorological Office has published, as part i. of 

 vol. xxxi. of its Annates, a very complete summary of the 

 mean temperature of Italy. The main part of the volume 

 is devoted to tables giving the mean temperature for 

 decades, wherever possible, for each year of the period 

 1S66-1906. The mean temperature is computed from 

 observations taken at oh. and 21I1., and from daily read- 

 ings of maximum and minimum thermometers, by the 

 formula 5(9+2 i + max.-t-min.). Data are given for about 

 120 stations, though only a small number of these can 

 supply information for the whole period. The later 

 chapters contain summaries of the information given in 

 NO. 2 1/6, VOL. 87I 



the main tables. We find in them values of averages and 

 extremes for months, seasons, and years. Numerous plates 

 showing the geographical distribution add greatly to the 

 value of the work. The preparation of the data has been 

 in the hands of Dr. Filippo Eredia, whose name is a 

 guarantee for the excellent arrangement of the results. 



In 1908 a number of experiments carried out by Mr. 

 H. E. Watson, of Trinity College, Cambridge, added 

 about 200 new lines to the spectrum of neon, bringing the 

 total number of lines to 321. Further research, the results 

 of which are published in the June number of The Astro- 

 physical Journal (vol. xxxiii., No. 5, p. 399), has shown 

 that certain regularities, suggesting subdivision into 

 " series," occur in the oscillation frequencies of these lines. 

 The lines appear to be divided naturally into three groups, 

 one of 252 lines extending from the extreme red to A, 4071, 

 a second of 29 lines extending from A. 3754 to A. 3370, and 

 a third consisting of 40 lines between A. 3167 and A. 2736. 

 On investigating the oscillation frequencies, Mr. Watson 

 finds that there are distinct indications of regular differ- 

 ences which suggest the existence of a principal and two 

 subordinate series, in which the lines are grouped in 

 triplets and quadruplets with constant frequency differ- 

 ences, the whole arrangement resembling the blue section 

 of the red spectrum of argon investigated by Rvdberg. 

 The investigation of these brighter lines and of the 

 numerous weak lines is being continued, and it is hoped 

 that, by methods not purely mathematical, a further 

 elucidation of this remarkable spectrum will result. 



In the abstract of Prof. Silvanus P. Thompson's paper 

 on harmonic analysis, printed in Nature of June 29 

 (p. 607), it was stated that the process described to find 

 the coefficient of any term in the harmonic series set 

 down was subject to a limitation. This limitation was 

 expressed in the abstract issued by the Physical Society, 

 but was omitted in the abridgment published in Nature in 

 order to bring the report of the society within reasonable 

 j limits of space. 



OUR ASTRONOMICAL COLUMN. 

 A New Comet, 1911b. — A telegram from the Kiel 

 Centralstelle announces the discovery of a new comet by 

 Mr. Kiess at the Lick Observatory on July 6. At 

 iSh. 23.7m. (Lick M.T.) the position was 



R. A. =4h. 51m. 5i-8s., dec. =35° 15' 2" N. 



A later telegram gives the position on Julv 7, at 14I1. 39-7m. 

 (Lick M.T.J, as 



R.A. = 4h. 52m. 54s., dec.=34° 52' 17" N. 

 The comet is fairly bright, magnitude 90, and has a tail, 

 but its position, about ij° north of ( Auriga;, makes it a 

 difficult object to observe in these latitudes. At 1 a.m. 

 the altitude of 1 Auriga? is about S°, and its direction is 

 north-east. 



Nova Lacert.-e. — No. 5, vol. xxxiii., of The Astro- 

 physical Journal contains a note by Prof. Frost discussing 

 the observations of Nova Lacertse and its spectrum, madi 

 at the Yerkes Observatory between December 31, 19 10, 

 and May 6. 



A suspected nebulosity around the star, shown on the 

 earlier photographs, was not confirmed by later observa- 

 tions with the telescope readjusted. Despite its distinctly 

 red colour, the light from the nova was found to be 

 strongly actinic, a phenomenon accounted for by the con- 

 siderable extension of the spectrum into the ultra-violet. 

 With the 40-inch telescope, Prof. Barnard found that a 

 sharp crimson image of the nova, due probably to Ho, was 

 formed 9 mm. further from the object-glass than the usual 

 image, which conformed with the ordinary stars. 



Two series of spectrograms were secured, one with the 

 Bruce spectrograph, the other with an objective-prism 



