540 
handbook, which is accompanied by an excellent map 
the distribution of the Government forest 
areas in India and Burma, is divided into three parts. 
The first part deals with the distribution and classifi- 
cation of the many types of forest found in British 
India, with notes on the financial working of this 
enormous State property; the second with eighty of 
the commoner timber trees of India and Burma, ex- 
plaining briefly the distribution, quality, and uses of 
the timber, its approximate value and yield in various 
localities, and so forth; the third with the minor pro- 
ducts, such as gums, fibres, resins, tan and dye pro- 
ducts, oil seeds, drugs, spices, bamboos, and a variety 
of others. The work is illustrated by several plates, 
and there is a comprehensive index of vernacular, 
English, and scientific names. 
showing 
In The South African Journal of Science for June, 
Prof. E. H. L. Schwarz continues his comparison of 
the Witwatersrand area and the Cape Province, and 
expounds the probable relations of the network of 
dolerite dykes in the Karroo area to an unseen lacco- 
tion theory to account for the bringing of igneous 
matter into place, and he holds that unsuitable sub- 
stances become drained off to lower depths. New 
material, however, is added to the upper layers of the 
crust, and the resulting increase in bulk has set up 
thrusts which have influenced the slope of the folds 
in the coast-ranges of the Cape Province. The Bush- 
veld granite, from the same point of view, has caused 
repeated folding in the bankets of the Rand. 
Dr. W. F. Hume has again earned the gratitude of 
geologists by publishing ‘‘Explanatory Notes to 
Accompany the Geological Map of Egypt” (Cairo: 
Survey Department, 1912, price 10 P.T.). A large 
amount of stratigraphical information is embodied in 
a series of tables, and the coloured longitudinal 
section across Egypt will be useful to many teachers. 
The relations of the Cenomanian limestones north of 
latitude 27° 50! to the Nubian sandstone are interest- 
ingly stated. 
AN interesting article on ‘‘Wind and Weather in 
the Adriatic,” by Prof. E. Mazelle, director of the 
Marine Observatory at Trieste, is printed in the 
Osterreichische Rundschau (vol. xxxi., part iii.). 
After giving a popular explanation of conditions 
obtaining in barometric maxima and minima, in 
connection with gradients, rotation of the earth, and 
centrifugal force, the author gives a very instructive 
account of the prevalent winds in the above sea, viz. 
the cold and dry north-east wind (bora) and the warm 
and moist south-east wind (sirocco). The bora 
occurs both in cyclonic and anticyclonic conditions ; 
in the first case the depression lies in the Mediter- 
ranean or in the Adriatic, and the weather is usually 
rainy. In the second case the bora is mostly re- 
stricted to the coastal districts, and is very violent and 
gusty. The greatest velocity observed at Trieste was 
84 miles an hour (? factor 3); during gusts the 
velocity exceeds 100 miles per hour. The sirocco also 
occurs both in cyclonic and anticyclonic conditions. 
In the former case the rainfall in the southern 
NO. 2230, VOL. 89] 
NATURE 
| of the absolute temperature of the gas. 
[JuLy 25, 1912 
Adriatic reaches abnormal amounts, and near the Gulf 
of Cattaro one of the wettest spots of Europe is to 
be found. The anticyclonic sirocco, caused by high 
| pressure east and south-east of the Adriatic, is the 
more violent of the two, and is only occasionally 
accompanied by rain. 
Wiru reference to the meteorological charts of the 
great oceans and lakes’ published by the U.S. 
Weather Bureau for August, we wish to direct atten- 
tion to a very useful set of charts showing monthly 
wind directions over the monsoon area of the North 
Indian Ocean, prepared by Mr. W. E. Hurd. The 
charts are accompanied by an interesting discussion 
of the usual behaviour of the winds over the seas on 
both sides of the great Indian Peninsula which 
“causes the most important phenomenon of the mon- 
soon, the summer rains, or the south-west monsoon, 
by its influence in changing the winds.” The 
gradual overpowering of the north-east trade-winds 
by the south-west monsoon as the warm season draws 
4 sae _ on is clearly shown by the monthly wind-stars. 
lite below. He is a strong supporter of the assimila- | 
AccorpD1nG to the kinetic theory in its simplest form 
the viscosity of a gas should vary as the square root 
The con- 
siderable deviations from this law found experimentally 
were first explained by Sutherland in 1893. He 
showed that the molecules exert an appreciable attrac- 
tion on each other before an encounter actually takes 
place, and that if this attraction is taken into account 
the viscosity should vary as the square root of the 
absolute temperature t, divided by 1+c/t, when c is a 
constant for each gas. This expression has been veri- 
| fied by experiments on many gases at temperatures 
above o° C. According to the Verhandlungen of the 
German Physical Society for May 15, Dr. O. Zimmern 
has determined the viscosity of ethylene and carbonic 
oxide at temperatures down to —150° C., and finds 
that Sutherland’s expression no longer holds at these 
low temperatures. The deviation is slight in the case 
of carbonic oxide, but considerable in the case of 
ethylene. In both gases the viscosity is greater at 
low temperatures than the formula makes it, with the 
value of c for higher temperatures. Dr. Zimmern 
finds that the density of the gases is also high at 
these temperatures, and is disposed to attribute the 
high values of both quantities to polymerisation in the 
gases at low temperatures. 
Tue July issue of The Chemical World fully main- 
tains the high standard of the six preceding numbers. 
The editor has produced an attractive blend of modern 
technical and analytical practice with advanced 
scientific research. 1n the current number, the tech- 
nical papers deal with the new industry of manu- 
facturing autogenously welded aluminium tanks and 
vessels, the manufacture of ‘‘Mond gas,” the treat- 
ment of water by the ‘‘Permutit’’ system and its 
sterilisation by the addition of excess of lime. The 
analytical papers deal with the estimation of potash 
in fertilisers, soil extracts, and plant ashes by the 
use of perchlorate instead of platinum salts, the ex- 
amination of cellulose, the estimation of nickel and 
cobalt with the help of dimethylglyoxine, and of 
