September S, 1904] 



NATURE 



459 



In the first part of the Bulletin of the Imperial Society 

 of Naturalists of Moscow, Mr. J. Gerassimow adds another 

 paper to his contributions to the physiology of the cell. 

 In cultures of Spirogyra crassa and allied species he obtained 

 abnormal cells, without nuclei, or with excess of nuclear 

 matter, or with two nuclei, by cooling the cultures in which 

 the filaments were in an active stage of division. The 

 result of changing the proportion of nuclear substance to 

 cell contents was to cause irregularity of growth, so that 

 where the nuclear substance was in excess, cell division was 

 retarded, but general growth accelerated. 



We have received a copy of a pamphlet entitled the 

 " Advantages of Ambidexterity," which may be obtained 

 from Messrs. Sampson Low, Marston and Co., Ltd., 

 price 6d. The booklet contains a lecture, delivered before 

 the .Ambidextral Culture Society by the honorary secretary, 

 Mr. John Jackson, dealing with the " advantages accruing 

 to any and every individual who may acquire the faculty of 

 using both hands with equal facility." 



An unpretentious magazine has just appeared under the 

 title of Discovery ; and it merits encouragement because its 

 aims are to publish trustworthy information on scientific 

 and other topics. In the first number. Dr. J. Oldfield 

 writes on diet, Dr. Edith Temple Orme on the modern 

 education of women, Mr. A. A. Buss on spectroscopy, and 

 Mr. A. C. D. Crommelin on the total solar eclipse of 

 August 30, 1905. Other subjects of popular interest are 

 dealt with in shorter contributions. The editor is Mr. G. 

 McKenzie Knight, and the London agents Messrs. Bensberg 

 Bros., 7 Electric Parade, Seven Sisters Road, N. 



The Cambridge Scientific Instrument Company has just 

 issued a useful illustrated list under the title " Technical 

 Thermometry." It is a new, revised, and enlarged edition 

 of an earlier catalogue entitled " The Measurement of 

 Temperature by Electrical Means." Copies of the list may 

 be obtained on application to the company. Among the 

 chief contents may be mentioned sections dealing with 

 electrical resistance thermometers, thermoelectric thermo- 

 meters, continuous temperature recorders, and electrical 

 resistance furnaces. The excellent illustrations and full 

 descriptions will render the list very serviceable to teachers 

 and investigators. 



OUR ASTRONOMICAL COLUMN. 



The Line Spectrum of Copper. — Some exceedingly 

 interesting results have been obtained by Mr. A. S. King 

 at Bonn during a detailed study of the line spectrum of 

 copper under many various conditions of arc and spark 

 discharges. Mr. King suggests that an accurate knowledge 

 of the conditions which produce spectral changes can only 

 be obtained by the detailed study of each element under 

 every possible condition of temperature, vapour pressure, 

 and electrical excitation, and to this end he has commenced 

 with the line spectrum of copper. 



He found that on using a high voltage, but small current, 

 in producing the arc spectrum, the " spark " lines were 

 shown on his photographs, and he attributes this pheno- 

 menon to the frequent interruptions of the arc producing 

 electrical conditions similar to those obtaining in the spark 

 discharge. .-Xgain, in the spark, he photographed the spec- 

 trum of the green luminous vapour outside the direct path 

 of the spark, and found that whilst the air spectrum was 

 almost entirely eliminated, there were very few changes 

 amongst the intensities of the copper lines. As this outer 

 layer would have, presumably, the same electrical conditions 

 as, but a lower temperature than, the spark track, he 

 suggests that the experiment affords strong evidence that 

 the electrical condition, rather than the vapour density or 



NO. 18 19, VOL. 70] 



the temperature, is the governing factor in producing the 

 various types of spectra. 



Mr. King gives a table of the lines which he has studied, 

 showing the behaviour of each line under the different con- 

 ditions, and he also describes the experimental methods and 

 the results obtained when the temperature, pressure, &c., 

 were varied (Astrophysical Journal, No. i, vol. xx.). 



Ephemeris for the Return of Encke's Comet. — A further 

 extract from the ephemeris for the approaching return of 

 Encke's comet, published by MM. Kaminsky and 

 Ocoulitsch in No. 3962 of the Astronomische Nachrichten, 

 is given below : — 



Ephemeris oh. {U.T. Berlin). 



1904 a(app.) 6(app.) log r log A 



h. m. s. , , 



. 0-3183 ... 01097 



. o'3094 ... o'o828 

 . 0-3002 ... 00551 

 . 02906 ... 00266 

 02806 ... 9 '9974 

 . 02702 ... 9'9677 

 ■ 0'2593 ■■ 99377 

 .\ccording to the above, the comet should apparently be 



situated about half-way between ;8 Arietis and a Triangulum 



on September 18, and, travelling thence in a W.N.W. 



direction, it should arrive very near to v Piscium on 



October 2. 



Supposed Relation between Sun-spot Minima and 

 Maxima Intensities. — From an analysis of Wolfer's 

 relative numbers, M. Angot believes that he has discovered 

 a connection between the intensity of a sun-spot minimum 

 and the intensity of the succeeding maximum. 



.According to a table prepared by him, and published in 

 No. 4 (1904) of the Comptes rendiis, a minimum during 

 which the number of spots is very small is followed by a 

 maximum in which the spots are correspondingly few. 



In accordance with this theory, the maximum now 

 approaching should be a feeble one, the relative number 

 for the spots not exceeding 70 or 80, because the relative 

 number for the past minimum was very small, viz. about 3-0. 



Ephemeris for Comet Tempel,. — A continuation of the 

 ephemeris for Tempel 's second comet during the approach- 

 ing apparition, taken from the daily ephemeris published 

 by M. Coniel in No. 3962 of the Astronomische Nachrichten, 

 is given below : — 



Ephemeris I2h. (lU.T. Paris). 



1904 a app. S app. log. A I : >--a2 



The comet is due at perihelion early in November. On 

 September g it should apparently be between one and two 

 degrees south of ;3 Librse, and on October 2 about one 

 degree south of 4> Ophiuchi. As this comet is likely to be 

 only a faint object during this apparition, it may be a 

 difficult one for observers in this country. 



Direction of the Sun's Proper Motion. — In No. 3961 

 of the Astronomische Nachrichten Prof. Kobold discusses 

 the proper motions of 144 stars chiefly taken from the 

 catalogues of Porter and Bradley. 



From the discussion he deduces the position of the anti- 

 apex of the Sun's-Way, and finds it to be a point near to 

 a .Argus having as its coordinates 



A=i59°-6, D=-S4°.7. 



As a general result, he states that the stars, of 

 which the motions are perpendicular to the parallactic 

 motion, are situated in preponderating numbers in a zone 

 which passes through the apex and anti-apex, and runs 

 perpendicular to the plane of the Milky Way, the point 

 towards which they appear to be travelling being situated 

 near to a Argus. 



