APRIL 29, 1897] 
end URE 
603 
violently at times, for we read that “the tendency to 
twist itself on the twig’s part was so great that on our 
holding firmly on to the ends it split and finally broke off.” 
We are even given the name and address of a 
“successful water-finder,” “who states that he is only 
affected by running water and quite passive to stagnant.” 
He says that “various kinds of wire or a watch-spring 
answer the same purpose as a twig or rod. A large 
number of people have the power to a certain extent.” 
He adds, “I now use my hands alone, holding them out 
with palms towards the earth. I reckon the rod as an 
instrument only, and that the power itself is in the 
person.” 
On the same page, however, the last conclusion of the 
water-finder is contradicted by the experiences of a 
certain noble Lord with another ‘“ well-known ‘dowser’ 
or water-finder” (name and address given), for we read 
that “the effect produced on the twig emanated from a 
power outside himself.” Moreover, the author states 
that “It” (the divining-rod) “is said to be still in vogue 
in Pennsylvania for petroleum, and in Cornwall for 
metallic lodes.” 
A very useful instrument apparently, and it seems a 
pity that its use is not better appreciated. The only 
form of “divining-rod” on which I should put the 
least trust, is one which may be seen nowadays 
carried about the streets of London by officials of the 
water companies, whose duty it is to detect “under- 
ground water” running to waste. Their instrument is 
certainly in the form of a rod, but it may be likened to 
a stethoscope, and its use depends upon its well-known 
acoustical properties rather than upon any mystic force 
still unclaimed by science. 
The statements about the dissolved gases in water are 
exceedingly loose. On p. 251 we read that “a fully 
aerated water contains about 6 cc. of dissolved oxygen 
per litre.” This is perfectly true for a temperature of 
22° C., but for the cold water of winter 9 cc. is nearer 
the mark. A few words more would have explained the 
influence of temperature on the solubility of gases in 
water. On pp. 12-13, too, the following statement is 
misleading. ‘“ Water can dissolve at ordinary tempera- 
tures about its own volume of carbonic acid, 3 per cent. 
of oxygen and rb} of nitrogen.” Coming as it does after 
references to the fact that a fully aerated water contains, 
in the dissolved state, the natural constituents of the 
atmosphere, oxygen, nitrogen and carbonic acid, and 
that these gases are given off on boiling, one naturally 
concludes that these figures refer to the relative pro- 
portion of the three gases so dissolved from the 
atmosphere ; but such is not the case, the figures refer 
to waters artificially saturated in the laboratory with the 
three gases in the pure state, and not mixed together as 
in atmospheric air, a fact which is not made clear. 
Naturally aerated, pure water contains, as a matter of 
fact, just about double as much nitrogen as oxygen. 
Again, on p. 191, the following inadequate statement is 
found: “ Among the gases dissolved by water from the 
atmosphere, carbonic acid, being the most soluble, .. . 
occurs in the largest proportion.” It is perfectly true that 
carbonic acid is the most soluble of the three gases of 
the atmosphere, but under the law of partial pressures, 
its greater solubility is more than counteracted by the 
NO. 1435, VOL. 55] 
small proportion of that gas present in the mixture, the 
result being that nitrogen (although having the lowest 
solubility of the three) occurs in the largest proportion, 
on account of its being present in the atmosphere in 
much greater proportion by volume than either oxygen 
or carbonic acid. Actual analyses of the gases given off 
on boiling in vacuo, from natural water having a surface 
freely exposed to air, often show less carbonic acid 
than nitrogen ; but if the water has passed through strata 
containing carbonic acid, or is very impure, and bacteria 
are thriving in it and producing carbonic acid, this gas 
may exceed the nitrogen in volume ; but in these cases 
the gas is not dissolved from the atmosphere, and in 
fact the excess diffuses into the atmosphere under 
conditions of perfect aeration. 
Notwithstanding the defects which have been noted, 
the book is one which is well worth reading by 
“members of local authorities, sanitary officers, and 
others,” for whom the book is avowedly written, who 
desire a general rather than a special knowledge of the 
present aspects of the subject, with all the recent 
advances which have been made in it. Nevertheless, as 
a little knowledge is a dangerous thing, local authorities 
will do well, when face to face with a water problem, to 
take the opinion of experts, and regard any knowledge 
gained by the perusal of this book as a_ negligible 
quantity where practical decisions have to be made 
regarding water supply or water purification. 
For the serious student of the subject, who wishes 
actually to perform the chemical and_ bacteriological 
examination of water, or to make an independent inter- 
pretation of the results of analyses, the volume will be of 
little value. JosEpH LUNT. 
THE LAND OF THE LAMAS. 
Mongolia and the Mongols. Results of a Journey made 
to Mongolia in the Years 1892-1893. By A. Pozdnéeff. 
Vol. i. Published by the Russian Geographical Society. 
4to, pp. 696, with many photo-engravings. (Russian.) 
(St. Petersburg, 1896.) 
HE author of this work is a well-known specialist in 
Mongolian and Manchurian dialects. He visited 
Mongolia, for the first time, in 1876, and brought home a 
remarkable collection of 972 volumes of both printed and 
MS. works on the history of Mongolia, which prove that 
our former conceptions of Mongolian historical literature, 
as being entirely permeated with an ultra-Buddhist spirit, 
were utterly incorrect. For the last fifteen years, M. 
Pozdnéeff was professor of Mongolian dialects and litera- 
ture at the St. Petersburg University, and he has published 
a great number of smaller monographs on different sub- 
jects connected with Mongolian literature and administra- 
tive organisation, as well as a big work on Mongolian 
monasteries. His name is not unknown either in this 
country, as he edited for the Bible Society various publi- 
cations in Mongolian, Kalmyk, and Manchurian. 
The present volume contains the diary of his first 
year’s journey, from Kiakhta to Urga, Ulyasutai, Khobdo, 
back to Urga, and thence to Kalgan, during which journey 
he visited several interesting monasteries on or near to his 
route, copying valuable inscriptions, minutely describing 
Buddhist, or rather Lamaite monasteries and temples, 
