604 
studying in the yvaszuns and in practice the adminis- 
trative organisation of Mongolia under both the Chinese 
rule and the modifying influence of Mongolian common 
law, aud paying attention at the same time to the interests 
of Russian trade in that immense territory, which begins 
to be dotted with Russian trade factories. In this work 
he was much helped by his wife, Mme. Olga Pozdnéeff, 
who travelled with him all the time, and by M. Fedoroff, 
who acted as a photographer of the expedition. Many 
of the photographs, chiefly of landscapes, ancient burial- 
places, old stone monuments, and monasteries, not to 
omit a portrait of the present grand-priest and “in- 
carnation” of deity—the Urga 4hutukhta—are most 
interesting. 
It is intended to publish the entire work in seven 
volumes, two of which will be given to the diaries of the 
expedition, one to the administrative organisation of the 
country, and one to Lamaism, which widely differs from 
the “Sakia-munism” that has lately been so much 
studied in Western Europe. The fifth volume will be 
devoted to various ethnographical materials, chiefly to 
folk-lore ; the sixth, to trade ; and the seventh, to a history 
of the prince families of Mongolia. 
It would be utterly impossible to sum up in this place 
the volume which we now have before us. The routes 
followed by M. Pozdnéeff being well-known to geo- 
graphers, only small additional geographical features 
could be gleaned here and there. On the contrary, the 
diary is full of small details about the features, the char- 
acter, and the aspects of the towns of Urga, Ulyasutai, and 
Khobdo ; the monasteries visited by the author; the 
organisation of the Chinese and Russian post in Mon- 
golia ; the relations between the local functionaries and 
the higher ones at Pekin, and so on. Some little scenes 
of the life of these functionaries, which are scattered 
through the diary, are worth pages of description, but 
they could hardly be mentioned without entering into 
many details. The same must be said of the monasteries, 
each of which has its own individual importance in 
the religious and political life of the country; Urga, 
for instance, which is the residence of the deity of 
Mongolia—the *£hutukhta—and the seat of a steadily in- 
creasing population of Lamas (they numbered 13,850 in 
1889), is the political centre of the country—“its St. 
Petersburg,” as the author says ; while the monastery of 
Erdeni-tsu is its ““ Moscow ”—that is, the heart of the 
country, and a living witness of all the chief events of the 
history of Khalkha Mongolia, where every temple and 
chapel, and every one of the ninety-two towers of its outer 
wall has a significance for the inhabitants. 
A special chapter, which has a real historical value, 
and gives a deep insight into the present conditions of 
Lamaite Buddhism under Chinese rule, is the chapter 
devoted to the “incarnations,” past and present, of 
éodisatva, in the persons of the subsequent “Au¢wkhtas, or 
grand priests and deities of Urga. These “incarnations,” 
as is known, take place in Tibet; that is, plainly speak- 
ing, a boy is selected for that purpose by the Tibet Lamas, 
and brought and enthroned with great pomp at Urga. 
The history of these “incarnations” for the last three 
hundred years is very edifying. 
The second volume will contain the diary of the expedi- 
tion during the year 1893. Peis. 
NO. 1435, VOL. 55] 
NATURE 
[APRIL 29, 1897 
OUR BOOK SHELF. 
Rough Notes and Memoranda relating to the Natural 
Ffistory of the Bermudas. By the late J. L. Hurdis. 
Edited by his daughter, H. J. Hurdis. 8vo, pp. 
vill + 408. (London: R. H. Porter, 1897.) 
THAT a group of islands where the list of resident native 
land birds comprises only seven species, in addition to 
which four maritime kinds frequent the coasts in summer, 
should be visited by no less than one hundred and 
twenty-eight other species, chiefly migrants, is a won- 
derful fact in natural history, and one worthy of the best 
attention of those interested in solving the problem of 
bird migration. To record the dates of the arrival and 
departure of these various migratory species, appears to 
have been the task set himself by the late Mr. Hurdis; 
and the present volume (portions of which have already 
appeared in another work issued as far back as 1859) is 
the result of his labours. 
The work is in journal form, and is written somewhat 
after the style of White’s “ Selborne”; and if it lacks the 
charm of that classic, this can hardly be considered a 
fault on the part of its author. At the end of the notes 
on the Bermuda birds, a list of the migratory species is 
given. And here it is to be regretted that the dates of 
arrival and departure are omitted; while we look in vain 
for any theories of migration, or hints as to whence the 
wanderers came and to what lands they departed. But, 
in justice to the author, it must be remembered that the 
notes were written ata time when the importance of such 
observations was not ranked as high as it is at the pre- 
sent day. 
It is not, however, by any means, to birds alone that . 
the notes are restricted ; and nearly a hundred pages are 
devoted to the other fere nature, as well as to plants, 
climate and meteorology, geology, and the early settle- 
ment of the islands. The editor has, on the whole, dis- 
charged her share of the task well, although it would 
have been better had the repetitions of the names of the 
regiments to which the author’s numerous fellow observers 
belonged been omitted. A few illustrations of birds and 
scenery would also have considerably lightened the perusal 
of a very readable book. Reve 
| Das Wesen der Electricitat und des Magnetismus auf 
Grund eines einhettlichen Substanzsbegriffes. By J G. 
Vogt. Pp. 134. (Leipzig, 1897.) 
IN this pamphlet the author proposes a theory of elec- 
tricity which is based on a new conception of the con- 
stitution of ether and matter. This conception of matter 
supposes that all bodies and the ether are to a certain 
extent continuous and made of the same material, there 
being in all cases an initial and final condition both of 
molecules and ether. 
The reason for this new proposal seems to be more 
sentimental than substantial. The author does not con 
sider that the modern molecule is an interesting body, 
as it has no object of its own in existence. The follow- 
ing sentences on page 7 of the introduction fairly repre- 
sents the author’s feeling on the subject :—“Es giebt 
nichts absurderes als der moderne kinetische Substanz- 
begriff nach welchem die Materie aus Atomen oder 
diskreten Massenteilchen besteht, die in der mono- 
tonsten Weise durch alle Ewigkeiten hin- und her- 
schwingen. Etwas stupideres und sinloseres ist kaum 
denkbar, und nur trockene, vom biicherstaube der 
Jahrhunderte verschiittete Physiker konnten eine solche 
trostlose Idee aushechen.” 
The leading idea which the author introduces is that 
space is filled with continuous matter, and that there is 
distributed through it centres of condensation. Surround- 
ing each of these centres is a quantity of matter, which 
forms a sphere. The material inside these spheres is 
always tending to become more condensed whether the 
sphere belongs to the ether or to an atom, which is 
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