July 27, ]SS:J.] 



SCIENCE. 



Ill 



well as with the temperature. At temperatures ran- 

 ging approximately from 20° to 30° C, about half as 

 much water was retained in a half-saturated as in 

 a saturated atmosphere. As the temperature was 

 raised, more water was absorbed from the saturated 

 atmosphere, but less from the half-saturated one. — 

 {Rep. Cal. coUerjc (I'jr.. 18S2, 52.) H. P. A. [110 



Influence of organic manures on temperature 

 of soil. — In expeiiineiits on this subject. K. Wagner 

 finds that organic manures raise the temperature of 

 the soil to an e.xlent increasing with the quantity 

 of the manure, the temperature of the soil, and its 

 moisture, so long as the latter is not in such excess as 

 to hinder access of oxygen to the organic matter, or 

 to cool tlie soil too much by its evaporation. Porosity 

 and ready decomposability on the part of the manure 

 favor the action. The increase of temperature is 

 greatest at first, may continue from four to twelve or 

 more weeks, but under practical conditions is too 

 small to be of much significance. — (Forsc/j. ayr. 

 phys., V. 37:!.) u. i'. a. [m 



Moisture of the soil. — lu pot-experiments with 

 peat, Ileinrich obtained the largest crop when the 

 peat contained sixty per cent of the total quantity of 

 water which it was capable of containing. Earlier 

 experiment by Hellriegel on sandy soil gave nearly 

 the same results. When the moisture of the peat fell 

 below twenty per cent of its water-capacity, no crop 

 was obtained, while in case of sand a small crop was 

 obtained when the moisture was only ten per cent of 

 the total water-capacity. — (Died, cenlr.-blatt., xii. 

 10!).) H. I'. A. [112 



GEOLOGY. 

 Lithology. 

 Cleopatra's Needle. — In a paper by Dr. P. Frazer 

 is given a description of some thin sections of the 

 New- York obelisk, made by Prof. A. Stelzner of 

 Freiberg, accompanied by four lithographic plates. 

 The rock is composed of fresh microcline, showing in 

 polarized light its characteristic grating; oligoclase. 

 somewhat decomposed, and showing fine twinning 

 striation; quartz in grains and granular aggregates, 

 containing fluid cavities, trichites, and hematite 

 plates; light green hornblende with irregular outlines; 

 biotite in large brown, translucent scales; titanite in 

 numerous small yellowish-red grainsj water-clear 

 acicular apatite crystals; magnetite in opaciue irregu- 

 lar grains and in octahedrons; minute zircon crystals; 

 yellowish-green needles of epidote and viridite. A 

 granite from Germantown was regarded as similar 

 to the Syene granite. The former is composed of 

 microcline, plagioclase, quartz, hornblende, biotite, 

 muscovite, titanite, etc. Frazer gives the lileratiire 

 of the subject. — {Trann. Amer. inst. min. enf/., 

 lioslon mertinij.) m. e. w. [113 



Journalistic lithology. — A weekly journal was 

 established last year in England on the peculiar plan 

 of publishing descriptions of microscopic slides, with 

 figures of the same, while duplicates of the described 

 preparations were to be sent to every subscriber. 

 This method, if under the direction of competent 

 specialists, would serve as a valuable means of home 



training for those who are unable to place them- 

 selves under the direct instruction of competent 

 teachers. It promised twenty-six histological, eigh- 

 teen botanical, and eight lithological sections a year. 

 The lithological descriptions, so far, have embraced 

 the following rocks: pikrite, dolerite, diabase, red 

 and white syenite, and serpentine, with some biblio- 

 graphical lists. While the journal contains some 

 matter of interest to lithologists, it is, on the whole, 

 a disappointing and unsafe guide for a student. In 

 some cases the style of the lowest grade of " popular 

 scientific lecturers' has been adopted; and the phrase 

 ' plugs of exosmotic transference,' used for veins, is 

 too good to be lost. — (Studies in microscopical sci- 

 ence, London, 1882-83.) M. E. w. [114 



METEOROLOGY. 

 Sun-spots. — At the university observatory at 

 Kome on' 2fi9 days in 1881, and 2SI0 in 1882, Tacchini 

 has made observations of sun-spots. He shows that 

 in 1882 there was an increase in spots over 1881. 

 The meandaily number by months was, in 1881. iy..55, 

 and, in 1882, 22..57. There were peculiar maxima in 

 the number in April and November, 1882. Taking 

 each period of constant activity in the daily observa- 

 tions in 1882, a second maximum and minimum 

 period appears at the half sun's rotation. For the 

 faculae we also find that the increase is less with the 

 growth of the spots; the yearly mean in 1881 being 

 8S..'ifi, and, in XS82, SL.'JS. It is believed from the 

 character of the sun's activity at the last maximum 

 period, as compared with the present, that the maxi- 

 mum spottedness will occur in IS83. —{Naturl'or- 

 scher, May 12.) ii. A. ir. [115 



PHYSICAL GEOGRAPHY. 



Artesian iwells in Algeria. — In the south of the 

 province of C'onstantiue, Algeria, the boring of arte- 

 sian wells, begun in 18o0, was continued with re- 

 newed activity, after the interruption occasioned by 

 the Franco-Prussian war, under the direction of M. 

 Jus. At the end, of 1879 the long line of wells fol- 

 lowing the AVady Rir, between Biskra and Tugurt, 

 included 434 sunk by the Ar.ibs, and yielding G4,000 

 litres a minute, and OS bored by the French, yielding 

 113,000 litres. In the same decade, the number of 

 jialm-trees in the oases had increased from 359,000 

 to 517.000; of fruit-trees, from 40,00ii to 90,000; of 

 inhabitants, from 0,672 to 12,827. During the first 

 half of 1880, twelve new wells were bored, yielding 

 22,000 litres, and, at the end of 1881, the total supply 

 of water from these underground sources was 209,- 

 OlMl litres a minute. —(J. J. Clamageran, Uev. geogr. 

 (•/ifeniKi., 1883. 43.) [116 



Currents of the Pacific Ocean. — Antisell dis- 

 cusses the general motion of the warm currents of 

 the western and northern Pacific, brings together a 

 number of data not before correlated, illustrates them 

 by maps and diagrams, and comes to the conclusion 

 that, 1°, the warming influence of the North Pacific 

 is the Kurosiwo, the motor power of which is the 

 south-west monsoon, blowing from April to October; 

 and, 2°, that the North Pacific Ocean has practically 



