650 

ok 
mints, ashes,”’ etc. Eudesmin is a particularly 
interesting substance, and occurs in the kinos of some 
species to the extent of ten per cent. 
The address also dealt with the chemical peculi- 
arities of the Australian Conifer, and in addition 
with the inorganic constituents peculiar to Eucalyptus 
trees, instancing the small amounts of mineral matter 
secreted in the timbers of those species which often 
occur as very large trees, such as E. vegnans, E. 
pilulavis, etc., a condition that suggests the reason 
for their continued growth and great size. 
The occurrence of manganese, and its importance, 
were also discussed, the conclusions being based 
upon the results of much experimental work. It 
was shown fairly conclusively that the presence of 
manganese in such minute quantities cannot be con- 
sidered as accidental, but a necessary constituent for 
successful growth of these trees, and that some species 
belonging to certain groups require a larger amount 
of manganese than is necessary for the growth of 
those belonging to other groups. The whole question 
evidently hinges around the action exerted by the 
enzymes in the structural formation of forest trees 
and their chemical constituents, and is thus a subject 
requiring long-continued chemical research and ex- 
periment before a reasonable solution of the problem 
can be expected. 

Sunshine-Recording. 
[X the sunny southern countries of Europe less 
general interest appears to be taken in the 
recording of sunshine duration than is the case in 
England, where a certain therapeutic importance is 
attached to an allotment of sunshine which in winter 
undoubtedly falls below the optimum, although 
probably not to a greater extent than it rises above 
the optimum during a Mediterranean summer. 
However this may be, it is interesting to find the 
subject discussed in a short article by Guilio Grab- 
lovitz in the comparatively new Italian publication 
La Meteorologia Pratica for July and August 1922. 
Various objections are raised to the continued use 
of the Italian words insolazione and soleggiamento 
to denote sunshine, the term eliofania being advo- 
cated instead, which would be anglicised to heliophany. 
It appears that the two former terms have medical 
significance in connexion with bad and good effects 
of exposure to the sun, from which our corresponding 
word “‘insolation,’”’ which is virtually equivalent to 
the more familiar ‘‘ sunshine,”’ is free. 
Discussion in the paper turns upon the proper 
dates for replacing the equinoctial card by the 
summer and winter ones in the well-known Campbell- 
Stokes sunshine recorder, in which the sun’s rays, 
focussed by a glass ball, leave a charred record. It 
is argued that the dates officially adopted for the 
change, namely, February 22, April 20, August 23, 
and October 22, when the declination of the sun is 
12°, might with advantage be altered to March 1, 
April 11, September 3, and October 15, when the 
declination is 8°; because in the latter case, during 
the passage of the sun through a range of 47° between 
the solstices, the equinoctial, summer, and winter 
cards would each be used through an equal range, 
approximately of 16° (16 x3 =48), whereas in the 
adopted practice the equinoctial card covers a range 
of 24° (12 x4 =48). This is a purely technical point 
to be settled by reference to the design of the instru- 
ment; but on wider grounds, astronomical and 
climatic, the dates actually adopted seem more 
natural because, the solar declination being then 12° 
NO. 2793, VOL. IIT] 
as NATURE 

[May 12, 1923 
N. or S., that is, practically half-way between 0° and 
233° N. or S., they mark what should be regarded 
as the real boundary between the solstitial and 
equinoctial periods of the year. ’ a 
In connexion with sunshine-duration recorders, 
one can scarcely refrain from commenting upon the 
inadequate character of instruments which give no 
information about the quality or intensity of the 
recorded sunshine, and from expressing the hope — 
that these will gradually be superseded by radio- 
graphs like the Callender recorder and Angstrém 
pyrrheliometer, which indicate the amount of solar 
energy received in a given time. Such radiographs 
may not be all that is desired, but at least they show 
the difference between the intensity of insolation on 
different days, at different seasons, and in different 
latitudes or altitudes. They can, for example, 
differentiate in comparable measured terms between 
the fitful sunbeams of December and the fiery rays 
of June; or show, again, that a hot day in England 
with, say, an air temperature of 90° F. is thermally 
less fierce than a day in Italy having the same air 
temperature but under a force of insolation unknown ~ 
The point is that equivalent — 
in Northern Europe. 
air temperatures are not truly climatically equivalent 
unless associated with the same intensity of insola- 
tion, and it is well known what an important factor 
in the economy of living creatures is the direct 
radiation of light and heat. L. jC: .Weras 

Trieste and Marine Biology. 
D R. M. STENTA, director of the Natural History 
Museum in Trieste, delivered an address, in 
October 1921, at the Trieste meeting of the Italian 
Society for the Advancement of Science, on the 
important part played by Trieste in the study of 
marine biology, and the address has recently been 
published (Atti Soc. Ital. Progr. Sci.). 5 
Dr. Stenta referred to the observations of Abbot 
Fortis published in 1771 on the islands of the Quarnero, 
and those of Abbot Olivi (1792), who gave, in his 
“Zoologia Adriatica,’’ a catalogue of the animals 
of the Gulf of Venice. Almost all the naturalists 
who visited Trieste in the first half of last century 
were German ; of these, two may be named—I. L. C. 
Gravenhorst, who recorded (1831) the results of his 
studies on various molluscs, echinoderms, and Antho- 
zoa; and J. G. F. Will, who gave an account (1844) of 
the anatomy of Scyphozoa, ctenophores, and siphono- 
phores. K. E. von Baer came in 1845 from Russia 
to Trieste to search for larve of echinoderms, but the 
results in that and in the following year were not 
very satisfactory. His visit, however, was fruitful 
in another respect, for he encouraged Koch, a young 
Swiss merchant resident in Trieste and an ardent 
collector, in his project of founding a museum of 
the Adriatic fauna, which became the centre of studies 
on the Gulf of Venice. Johannes Miller spent the 
autumn of 1850 in Trieste working on the develop- 
ment of echinoderms and worms, and in the neighbour- 
ing bay of Muggia he discovered in Synapta digitata — 
the parasitic molluse Entoconcha mirabilis. 
Among many who worked at the museum between 
1850 and 1870 were Oscar Schmidt, who carried on 
researches on sponges; A. E. Grube, who examined 
the annelids and discovered the parasitic rotifer 
Seison nebaliae ; 
(1868) the remarkable sexual dimorphism in Bonellia 
viridis. In 1874 the Adriatic Society of Natural 
Science was founded, and the 27 volumes of its — 
Bulletin are rich in observations on the biology of 
the area. 
and Kowalevsky, who described — 
ee eS) ee ae 
