276 
NATURE 
[May 16, 1912 
great activity in tropical planting enterprise in recent 
years has resulted in a large demand for this quarterly 
bulletin, which is now considerably enlarged, and will 
be the means of publishing the results of investiga- 
tions of new raw materials from the Colonies and 
India carried out at the institute, and recent informa- 
tion regarding developments in tropical agriculture 
generally. This number (vol. x., No. 1) contains a 
concise introductory article on the history and 
activities of the institute, followed by articles dealing 
with the rubber resources of Uganda, the cultivation 
of cotton in Nyasaland and Uganda, the large de- 
posits of diatom earth in East Africa, hemp and hemp 
seed, cultivation and preparation of ginger, and the 
first part of a long and detailed account of the cocoa- 
nut and its commercial uses—to mention only a few 
of the interesting papers in this issue of nearly 190 
pages. A large number of reports on investigations 
of new Colonial products are included, and a special 
section of the bulletin is devoted to giving an account 
of recent developments of tropical agriculture through- 
out the world. 
THe pupils of Ferdinand von Richthofen have 
agreed to publish annually a collection of geo- 
graphical memoirs under the title of ‘‘ Mitteilungen 
des Ferdinand von _ Richthofen-tages,’’ to com- 
memorate their master, who passed away in 1905. 
The first part, issued by Teubner, of Leipzig, for 
IgIiI, appropriately contains three papers on China, 
that by M. Groll dealing with the progress that can 
now be made in the production of a general map of 
the country. The greatest difficulty still lies in the 
absence of details as to the relief. It seems un- 
fortunate that these papers cannot be published as 
special contributions to one of the recognised geo- 
graphical journals. 
From the issue of December last of the Monthly 
Weather Review of the Department of Marine and 
Fisheries, Canada, some interesting details are given 
of the highest and lowest temperatures in each 
province of Canada during that month. The highest 
temperature recorded was 65° at Alix, Alberta, on 
December 3, and the lowest was —59° on December 
28, at Fort William, in the same province. Other 
low temperatures recorded during the month were 
—51° at the Pas, Saskatchewan, on December 20, 
—50° at Swan River, Manitoba, on the same day, 
when —40° was recorded at Fort St. James, . British 
Columbia. 
Tue separately issued appendix No. 3 to the report 
for 1911 of the U.S. Coast and Geodetic Survey gives 
particulars of the magnetic observations made during 
the year ending at midsummer, I911. Of the 351 
land stations occupied during the year, seventy-one 
were old or ‘‘repeat”’ stations, and particulars are 
given of the values derived for the secular change 
of declination at these. Table I. summarises the 
results of the observations at the land stations, includ- 
ing nearly sixty stations along the Alaskan boundary, 
seven in Hawaii and one in British Columbia. 
Table II. gives particulars of observations made at | 
sea, in both the Atlantic and Pacific Oceans, by three 
vessels attached to the Survey. 
NO. 2220, VOL. 89] 
pages are occupied with a description of the land 
stations and their exact positions. 
Tue March number of the Journal of the Institu- 
_ tion of Electrical Engineers contains a summary of 
the theory of the production of electric oscillations 
by Mr. A. S. M. Sorensen. After two short para- 
graphs dealing with oscillations in a single circuit 
having capacity and inductance, and in coupled cir- 
cuits, he points out that in actual practice the capa- 
cities and inductances are not concentrated at par- 
ticular points of the circuits nor are resistances and 
damping constant. In the case of an arc in circuit 
he shows how by the aid of the ‘characteristic curve ” 
of the arc the main features of the oscillations pro- 
duced in the three most important cases can be traced 
without the necessity of appeal to the differential 
equation of the circuit. 
A yEAR ago Dr. K. Fredenhagen, of the University 
of Leipzig, described in the Physikalische Zeitschrift 
some measurements he had made of the cur- 
rents produced by the electrons emitted by 
metals at high temperatures. At the time 
he believed his results were free from secondary 
effects, but more recent work on the alkali 
metals distilled and tested in high vacua has, accord- 
ing to a short communication to the German Physical 
Society published in the Verhandlungen for April 15, 
convinced him that the whole of the current observed 
in such cases may be due to the reactions taking 
place between the metal and the trace of gas still 
present even in the highest vacua. Since the velocities 
of such reactions would follow exponential laws as 
the temperature increased, the currents obtained 
would be expressed by Prof. Richardson’s formula. 
In his presidential address to the Chemical Society, 
reprinted in the April number of the Journal, Prof. 
Frankland has directed attention to the extreme fre- 
quency with which the rupture of a “double bond” 
is accompanied by ‘‘trans-substitution.”” It has 
usually been thought that the addition of a substance 
XY to a compound such as maleic acid must result in 
the production of the cis-compound II., in which the 
radicals X and Y occupy the same positions as the 
ends of the broken bond. 
iB H ‘0,O0H H 
| \. CO.O 
X.C.CO.OH X.C.COOH 
| f = | 
VAC. O. OE - eUOae 
| mK | 
H Wf COOH COOH 
II. cés-Compound I, Maleic acid Ill. ¢xans-Compound 
This view was confirmed by the oxidation of maleic 
acid to meso-tartaric acid and of fumaric acid to 
racemic acid. 
H H. COOH Hu COOH) ET 
| - Bg | 
HO.c.cooH © \e HO.C.COOH 
| < | > 
YOO | 
HO.c.cooH =} iH HO.C.H 
| 
XN | 
COOH HO.0C% SH CO.0H 
H H 
gneso-Tartaric Maleic Fumaric Racemic 
acid acid acid acid 
But, so far from being the rule, the cis-substitution 
The last fifty-nine 1 shown above appears to be entirely exceptional, since 
