206 
NATURE 
[ DecEMBER 31, 1896 
this lake had no outlet, and was fed by a subterranean stream ; 
the surface was estimated at 1350 metres above sea-level, and 
the surface temperature of the water was 14° Réaumur. 
Director KELMERT has presented to the Prussian Academy 
of Sciences a memoir on the variations of the force of gravity 
along a line from Kolberg to the Schneekoppe, by Arnswalde, 
Gréditzberg, Grunau, and Giersdorf, founded on a combination 
of German and Austrian observations at twenty-two stations. 
A normal curve of change of intensity is drawn between the two 
points, and the departures from this curve at particular stations 
are discussed in detail. The A/2/thez/ungen of the Geographical 
Society of Vienna contains an abstract of the results, which show 
that an abnormal increase in the force of gravity can be traced 
to the presence of dense rock masses below the surface, and an 
abnormal decrease to the partial or total removal of unexposed 
strata. Under certain assumptions it is possible to estimate the 
thickness of these subterranean strata ; on the Pomeranian lake 
plateau a layer of about 216 metres in thickness is responsible 
for increased intensity, while near the Schneekoppe a decrease, 
which cannot be ascribed to lower density at the surface, is 
probably due to subterranean layers 200 metres in thickness. 
These disturbing elements do not in all probability lie deeper 
than 20 or 30 kilometres. The deflections of the plummet from 
the vertical are also discussed with interesting results; the 
maximum deflection, amounting to 18°1”, was observed at the 
Alter Bruch Station on the slopes of the Schneekoppe, at an 
elevation of 917 metres. 
In the current number of the 4//z det Lincez, Dr. G. 
Folgheraiter concludes his investigations on the state of terres- 
trial magnetism in the Etruscan epoch as revealed by obsery- 
ations of old vases (see p. 40). The results appear to indicate 
that in the eighth century B.c. the magnetic dip in Central Italy 
was small, and in the reverse direction to what it is at the 
present time, so that a magnetised needle at that epoch would 
have assumed a position with its south instead of its north pole 
pointing downwards. Some two centuries later, the declination 
seems to have approached the value zero, the earth’s magnetic 
field being nearly horizontal, while in many of the vases the 
direction of polarity is the same as at the present time. There 
are, of course, many difficulties in the way of drawing precise 
conclusions from these observations—such, for example, as the 
uncertainty as to the date of fabrication of the vases ; but the 
results are sufficiently consistent to establish the validity of the 
method. Dr. Folgheraiter points out that the prevalence of 
austral magnetism at the bases of Etruscan vases might be 
interpreted either on the supposition that the magnetic equator 
has been so displaced as to pass to the north of’ Etruria, or by 
admitting that the northern and southern hemispheres had their 
magnetic polarity opposite to that of the present time, and that 
the latter state may have been arrived at by successive variations 
in the magnetic declination. The present state of knowledge 
does not permit more weight to be given to one hypothesis 
than to the other; nevertheless, the author already has an idea 
of trying if it may be possible to throw some light on this 
question by means of suitable investigations. 
THE latest number of the Certralblatt fiir Baktertologie, Part 
ii., contains a paper by Messrs. Stutzer, Burri, and Maul, on 
the capability of growing on foreign culture media exhibited by 
the Bactllus xadicicola. These bacilli have attracted a great 
deal of attention recently in connection with Dr. Nobbe’s in- 
It will be remembered that Nobbe has isolated 
out seventeen or more of these nitrogen assimilating bacteria 
from the root-nodules of various leguminous plants, and has 
endowed them with the collective title of Nitragin. The present 
memoir describes some experiments made with these novel 
bacterial soil fertilisers derived from lucerne plants. Culture 
NO. 1418, VOL. 55] 
vestigations. 
media were prepaved from these plants, and also from white 
mustard plants, by adding to the infusions respectively derived 
from them, gelatine and grape sugar, the whole being then steril- 
ised as usual. Lwucerne-nodule-bacteria were inoculated on to 
both these different media, and their cultivation was carried 
on through several generations. Whereas on the lucerne gelatine 
the bacteria flourished abundantly up to the last, on the mustard 
gelatine they gradually faded away. It was next tried if these 
lucerne-nodule-bacteria could be induced to thrive on this 
mustard medium by gradually training them to become ac- 
customed to this foreign soil. In the course of six months these 
bacteria had completed their education, and they accepted the 
mustard gelatine as eagerly as they had before the lucerne 
gelatine. This highly successful result led the investigators to 
think that possibly in the interval these bacteria might have 
lost all taste for their original culture food, but inoculation from 
these mustard-grown bacilli on to lucerne gelatine showed that 
this anticipation was not justified, for they grew with their usual 
luxuriancy. It would be interesting to determine if by suitable . 
training nodule bacteria could be induced to fertilise or 
“‘nodulise” leguminous plants other than those from which 
they were originally derived. 
ARCHEOLOGISTS have long been puzzled over certain bronze 
objects about 3 inches in length, which consist of two rigid rings 
united by a short band, from which three spurs project. These 
may be found in collections of Etruscan, Roman. and Greek 
antiquities in museums, where they are usually labelled as bow- 
pullers. Mr. E. S. Morse, 
the Director of the Peabody 
Academy of Science, has 
been interested for seven 
years in these problematical 
objects, and now carefully 
describes and figures a num- 
ber of them in the Azil/etaz 
of the Essex Institute (vol. 
Xxvl., 1894, p. 141).. Some 
ten purposes have been sug- 
gested for their use; as a 
practical archer the author 
dismisses the bovw-puller 
hypothesis, and, indeed, he 
says he must ‘reluctantly 
yield the solving of the enigma to others, having got no nearer 
an explanation of it than when I first began.” Perhaps the 
‘most plausible view is that it may have been bound to the 
band to enable a chariot driver to hold the reins more firmly 
‘in driving. 
Dr. F. Terzner concludes in G/oéuws (Band Ixx. Nr. 18) his 
series of four articles on the ethnography of the Kaschuben of the 
Leba Sea, in North-west Pomerania. The Kaschuben are the last 
Slavoni¢ remnants of the Pomeranians in this district. He gives 
an interesting account of the folk-lore of this remote people, in- 
cluding some folk-songs, rhymes on grave-stones, and a few 
verses of children’s singing-games, among which is the widely- 
spread ‘‘ Ringel, ringel Rosenkranz”; but poor though the 
Kaschuben are in songs, they are rich in traditions and folk-tales. 
‘Stupid Hans,” who is so popular in German, Slavonic, and 
Lithuanian tales, plays the chief part in their marchen and 
narratives. Another important incident is ‘‘The Cheated 
Devil” ; ‘‘The Wild Huntsman” comes next in popularity to 
the Devil as every onehas seenhim, The articles conclude with 
sections on manners and customs and festivals. 
From the concluding summary of the paper on “‘ First 
Records of British Flowering Plants,” in the /Jow7nad of Botany, 
it appears that, of the 1440 species now reckoned as British, 510 
