5 o8 



NATURE 



[October 12, 191 1 



a special medium described in the paper, the author has 

 found as many as three millions of nitrogen-fixing Rhizobia 

 in 1 gram of agricultural soil. The foremost place in the 

 work of nitrogen fixation should, therefore, be given to 

 Rhizobium rather than to Azotobacter, until it is found that 

 the latter is at least half as numerous as the former. The 

 numbers of Rhizobia in the soil afford an indication of its 

 ative fertility. 



Cape Town. 

 Royal Society of South Africa, August 16.— Mr. S. S. 

 Hough, F.R.S., president, in the chair.- — L Peringuey : 

 A note on the Heidje Eibib, or stone mound of Namaqua- 

 land. The name Heidje Eibib is usually given to artificial 

 mounds of stone occurring in certain places in Namaqua- 

 land and elsewhere, the formation of which is ascribed to 

 the Hottentots, who whenever passing the spot add a 

 stone to the cairn, taking great care, however, that in so 

 doing their shadow is not projected on the mound. But 

 so far there was nothing to prove that these cairns were 

 really a kind of sepulture. Lately, however, one such mound 

 was opened, and it was found that the accumulation of 

 stones covered parts of a body ; the skull is, to all appear- 

 ances, that of a Bush. But the Rev. Mr. Kling informs 

 the author that there are two kinds of Heidje Eibib. The 

 one opened is known as Heidje Eibib Garedje, and would 

 be the grave of a Bush witch doctor, erected by his people. 

 But it is not yet proved that the Hottentot's Heidje Eibib 

 is a grave. — E. Nevill : The secular acceleration of the 

 orbital motion of the moon. The paper begins with a 

 critical examination of the records of the principal ancient 

 eclipses of the sun mentioned as being total, or very nearly 

 total, by different Assyrian, Babylonian, Grecian, and 

 Chinese records. The exact conditions of each eclipse have 

 been calculated from the best modern theoretical data 

 according to Hansen's method of computation. As a 

 result, it is shown that with our present knowledge it is 

 not possible by any system of data consistent with the 

 modern observations of the sun and moon to bring all the 

 principal eclipses recorded by ancient authorities :is having 

 been total into accord with the tables. The second portion 

 of the paper assumes the existence of a secular accelera- 

 tion in the motion of the earth around the sun, and 

 proceeds to consider what might be the origin, and to what 

 degree the existence of this cause will modify the motion 

 of the different members of the solar system, and how far 

 the deduced consequences are in harmony with observation. 

 It is shown that the case of the terrestrial tidal effect due 

 to the action of the sun and moon does not form a con- 

 servative system, and that the principle of conservation of 

 angular momentum does not hold for any non-conservative 

 system -of forces. No other origin for a secular accelera- 

 tion being apparent, the great difficulty in reconciling t lie 

 consequences of such a secular acceleration with the known 

 motion of the sun and moon render it preferable to look 

 to one of the other permissible causes as a means of 

 reconciling the existing theories of the sun and moon with 

 the records of the ancient eclipses of the sun and moon. — 

 A. Theiler : Some observation^ concerning the trans- 

 mission of East Coast fever by ticks. In the experiments 

 it has been proved : — (i) That brown tick imago which as 

 larvae had become infected with East Coast fever, and 

 had transmitted the disease in their nymphal stage, 

 were no longer infective for susceptible cattle. Four 

 batches of ticks proved their infectivity in the nymphal 

 stage on eight animals, but in their adult stage failed to 

 transmit the disease to two susceptible animals. (2) Ticks 

 belonging to the same batches which were feeding on two 

 animals rendered immune to East Coast fever by inocula- 

 tion, in the nymphal stage, did not transmit the disease 

 in their adult stage to six animals, thus proving that the 

 brown tick which has become infected in one stage rleans 

 itself in the following stage by feeding on an immune or 



ptible animal. (3) Ticks which became infected with 



East Coast fever in their larval stage, and passed 



nymphal stag a 1 ibbit, did not prove to be 



ive in their adult stage for susceptible cattle. This 



nt that given above (2). showing that 



a tick lus.s its infectivity the first time it feeds on an 



11 ceptibli or immune to East Const fever. 



Ilean or infective ticks feeding on an animal which 

 ha- recovered from an attack- of East I do not 



NO. 2l8g, VOL. 87] 



transmit the disease in their next stage. This conclusion 

 is in support of experiments undertaken eight years ago 

 (vide Annual Report of the Government Veterinary 

 Bacteriologist, 1904-5). (5) It has been demonstrated that 

 certain batches of ticks collected at the same time, and 

 which fed under similar conditions, did not transmit the 

 disease in their next stage, even when infected in great 

 numbers and on numerous animals. Other batches of 

 ticks reared in exactly the same way and under similar 

 conditions only infected a few animals, whilst again other 

 ticks proved infective in almost every instance, even when 

 a minimum number were used. It is difficult to give an 

 explanation of this fact, but it is quite likely that outside 

 conditions have some influence. The ticks which did not 

 transmit the disease were bred during the coldest time of 

 the year. 



DIARY OF SOCIETIES. 



TUESDAY, October 17. 

 Faraday Societv, at 3. — Adjourned discussion : The " Paragon " Elec- 

 tric Furnace and Recent Developments in Metallurgy: J. Harden.— 

 Progress in the Electrometallurgy of Iron and Steel : Donald F. Campbell. 

 — The Hering " Pinch Effect " Furnace: E. Kilburn Scott. 



WEDNESDAY, October 18. 



Royal Microscopical Society, at S.— -Structural Details of Coscitw 



discus astcrompkalus : T. W. Butcher.— Abstract of Paper on the Wheal 



Plant: A. Flatters.— New British Enchytrceids : Rev. Hilderic Friend. 



— Instantaneous Exposure in Photomicrography : Walter Bagshaw. 



cal Society, at 8. 



FRIDAY, October 20. 

 Institution of Mechanical Engineers, at 8. — The Endurance 

 Metals ; Experiments on Rotating Beams at University College, Londo 

 E. M. Eden, W. N. Rose, and F. L. Cunningham. 



CONTENTS. pag 



Biological Philosophy. By J. A. T 4; 



Tides and Orbits 4; 



The Science of Modern Artillery. By Sir G. 



Greenhill, F.R.S 4, 



Insulating Materials and Armature Windings. By 



Prof. Gisbert Kapp 4' 



Agricultural Bacteriology. By R. T. H 4.' 



Our Book Shelf 4 



Letters to the Editor: — 



The Simultaneity of Certain Abruptly-beginning Mag- 

 netic Disturbances. (With Diagram.)— Prof. Kr. 



Birkeland . . 4 



The Library and the Specialist.— Dr. Thos. Muir, 



C.M.G., F.R.S. : The Wiiter of the Article . 4 



Two Urdesctibed Giraffes.— R. Lydekker, F.R.S. 4 

 The Distastefulness of Anosia phxippus. — R. I. 



Pocock, F.R.S .... 4 



The Arithmetic of Hyperbolic Functions. — Rollo 



Appleyard . . i. 



Hot Days in 1911. (With Diagram.) — Alex B. 



MacDowall 



Frequency of Lightning Flashes.— H. O. Weller . . 4S5 

 The Automatic Telephone Exchange. (Illustrated.) 



By Arthur Crotch . . 486 



The Summer of ion. By Chas. Harding 489 



A Volcanolog'cal Institute. By J. M 49° 



The Archaeological Department of India ... . 491 



Louis Joseph Troost 49 1 



Notes . . . 49 2 



Our Astronomical Column: — 



Beljawsky's Comet, 191 \g 49*> 



Quenissel's Comet, 1911/ 49 6 



Brooks's Comet, 191 1< 496 



The Sydney Observatory 497 



A New Minor Planet 497 



New Water Supply Works 497 



Precious Stones 497 



Mathematics and Physics at the British Association 498 

 Links with the Past in the Plant World. By Prof. 



A. C. Seward, F.R.S. 5° 2 



University and Educational Intelligence ... . 506 



Societies and Academies 5°7 



Diary of Societies 5°8 



