894 
NATURE 
[JUNE 30, 1923 

and an inner kernel with about the same percentage 
of an oil of different composition. Both these oils 
are of commercial value, and G. G. Auchinleck, in 
Bulletin No. 62 of the Department of Agriculture, 
Ceylon, estimates that 300,000 tons of kernels and 
100,000 tons of palm oil come on to the market 
annually. The French, English, and Belgians are 
in control in the various oil-producing areas of Africa, 
but the Dutch appear to be first in definitely under- 
taking the systematic plantation of the oil palm, 
some 28,000 acres being planted with this plant 
in Sumatra by 1922. If the somewhat uneven 
product and irregular supply from the palm’s natural 
habitat can be replaced by a trustworthy product 
developed from a systematic plantation industry, 
the African palm-oil trade will meet with a formidable 
competitor. British planters in the East would 
probably do well to study Mr. Auchinleck’s account 
of the oil palm and its product in this bulletin, and to 
watch the future history of the oil palms now planted 
at the Anuradhapura Experiment Station in Ceylon. 
UrREASE.—A powerful enzyme, which has the 
property of causing the rapid conversion of urea 
into ammonium carbonate, has been found in many 
plant tissues, especially seeds. That of the soya 
bean is the best known. Dr. W. R. Fearon, in the 
Biochemical Journal (vol. 17, No. 1, 1923), shows 
that what urease does is to split urea into cyanic 
acid and ammonia. He has isolated cyanic acid 
from solutions of urea under the action of the enzyme. 
The enzyme has no other action; cyanic acid in 
the presence of water rapidly undergoes spontaneous 
hydrolysis into carbon dioxide and ammonia. The 
facts can only be satisfactorily explained on the 
cyclic formula for urea put forward by Werner ; 
that is, 
O 
HN: CY | 
\NHS. 
The decomposition of urea by acids; alkalies, or heat 
proceeds along the same lines. We see also why 
urease does not decompose ethyl-urea or methyl- 
urea, not because of the nature of the enzyme, but 
because these substances do not yield cyanic acid. 
VALENCY OF Boron.—We have received from the 
Koninklije Akademie van Wetenschappen te Amster- 
dam a reprint of an interesting paper on ‘“‘ The 
Valency of Boron,” by Prof. J. Béeseken, from the 
point of view of atomic structure. He concludes 
that boron exhibits valencies of 3 and 5. 
SEPARATION OF THE IsoToPES oF MERCURY.—A 
detailed account of the partial separation of the 
isotopes of mercury by evaporation in vacuum in 
a large steel apparatus is given by Harkins and 
Madorsky in the March issue of the Journal of the 
American Chemical Society, The atomic weights of 
the heavy and light fractions differ by o'r unit. 
The partial separation is still a long and somewhat 
laborious process, but the authors state that they 
have designed an apparatus which would give the |} 
same separation in about thirty hours. The heavy 
and light fractions are still mixtures of isotopes, six 
of which, according to Aston, exist in the case of 
mercury. 
WEATHER AT HONGKONG DURING 1922.—The 
Monthly Meteorological Bulletin for December 1922 
contains “‘ detailed results of observations made at 
the Royal Observatory, Hongkong, and the daily 
weather reports from various stations in the Far 
East,’”’ prepared under the direction of Mr. T. F. 
Claxton. The part for December also contains an 
annual summary of the Hongkong observations 
NO. 2800, VOL. III] 

for the year 1922 and gives the mean and extreme 
values of the principal meteorological elements, 
with the normal values for the period 1884-1918. 
Tracks of the typhoons and principal depressions 
which occurred in the Far East during the year 
1922 are shown on two plates. At Hongkong the 
barometric pressure during 1922 ranged from 
30°445 in. during November to 29°174 in. during 
August. The air temperature ranged from 93°1° F. in 
August to 43°7° F. in November. The monthly mean 
was highest in July and lowest in January, the mean 
temperature for the two months differing by 22° F. 
For the thirty-five years the highest temperature — 
observed was 97'0° F. in August 1900, the lowest 
32°0° F. in January 1893. The total rainfall in 
1922 was 69°44 in., of which 17°54 in. fell in August, 
and rain fell on 154 days. The average total rainfall 
for the thirty-five years is 83°83 in., the average total 
rain in the four months May to August being 55°13 in. 
The greatest prevalence of wind is from the east. 
Values of magnetic elements are given for the 
year ; the means were Declination (west) 0° 21’-5, Di 
(north) 30° 460, Horizontal Force (C.G.S. Unit 
037279, Vertical Force (C.G.S. Unit) 0-:22194, Total 
Force (C.G.S. Unit) 043386. No mention is made on 
the title-page of the Bulletin that the results for the 
year and the cyclone tracks, as well as the averages 
for thirty-five years, are given, and a.casual reader 
might overlook this information, which is of primary 
importance. : 
EGypriAN PETROLEUM. — Heavy - grade Egyptian 
crude petroleum formed the subject of a paper by 
Mr. W. A. Guthrie read recently at the Institute of 
Petroleum Technologists. The oil chiefly discussed 
was the product of the well-known Hurghada 
(Rargada) wells, situated about 200 miles S.E. of 
Suez, on the western shore of the Gulf. This field 
was first developed in 1914, since when it has 
produced 1,201,868 metric tons of oil; its present 
output averages 3500 tons per week. Some pro- 
portion of the oil contains salt water up to 30 per 
cent., an emulsion which, though it has proved 
refractory to deal with, seems to respond to electrical 
dehydration treatment, a method not always com- 
mercially possible. The dry oil flashes below 45° F., 
and its s.g. ranges from 0°907 to 0'925. Its sulphur 
content varies from o’5 per cent. to 2°22 per cent. 
(comparatively low), while it yields 10-11 per cent. 
asphalt and 7-8 per cent paraffin wax : hence it may 
be classed as a true mixed-base oil. Distilled in the 
ordinary way, the crude oil gives 8 per cent. benzine 
and 15 per cent. kerosene, the residue (above 290° C.) 
constituting 76 per cent. Both the benzine and 
kerosene can be refined to very high-grade products, ~ 
while the residue is utilised for the production of solar 
or Diesel oil (43°2 per cent.), hard pitch (29°3 percent.), 
and inferior fuel-oil. The inclusion of an appreciable 
quantity of paraffin wax in the pitch is considered 
by the author to be advantageous rather than 
deleterious to its use for road surfaces, since theoretic- 
ally it should enhance chemical stability and render 
the material less liable to crumble or disintegrate 
under climatic variations or under ordinary wear 
and tear. The author dealt at some length with 
paraffin wax extraction, by no means an easy problem 
in this case, but this product actually finds little use 
within Egypt itself. One other interesting point 
mentioned in the paper was in connexion with the 
oil produced from the new field at Abu Durba, on 
the east shore of the Gulf; chemical and physical 
tests apparently show that this oil is an inspissated 
and oxygenated product of petroleum: it is of a 
very heavy asphaltic character and contains varying 
proportions of a waxy resin. 
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