582 
J 
Tue additions to the Zoological Society’s Gardens:during the 
past week include a Vervet Monkey (Cercopithecus lalandit) 
from South Africa, presented by Mrs. E. L. Francis ; a Chacma 
Baboon (Cynocephalus porcarius) from South Africa, presented 
by the 4th Co. Army Service Corps; an Anubis Baboon 
(Cynocephalus anubis) from West Africa, presented by Mr. 
R. D. Whigham; a Formosan Deer (Cervus taévanus ?) from 
China, presented by Captain Percy Scott,»H.M.S. Terrible ; 
three Herring Gulls (Larus argentatus), European, presented 
by Mr. F. W. Hunt; a Land Rail (Cvex fratensis), British, 
presented by Miss Elsie E. Hutton; a Schmidt’s Monkey 
(Cercopithecus schmidt2) from East Africa, a Black-cheeked 
Monkey (Cercopithecus melanogenys) from West Africa, two 
Rhesus Monkeys (AZacacus rhesus), an Indian Python (Python 
molurus) from India, a Brown Macaque (J/acacus arctoides) 
from Burmah, an Amphiuma (Amphiama means) from North 
America, a Lion Marmoset (A/¢édas rosalia) from South- 
east Brazil, two Eyras (Ze/és eyva) from South America, 
deposited. 
THE SCIENTIFIC AND TECHNICAL 
EXHIBITS AT THE ROVAL PHOTOGRAPHIC 
SOCIETY S EXHIBITION. 
VHs section cf the Royal Photographic Society’s exhibition 
appears to be rather smaller than on the two previous 
occasions, that is, since the larger accommodation of the New 
Gallery made it possible to represent adequately this side of 
photographic work. We hope that this is not an indication that 
the section is receiving less attention and is likely to suffer 
extinction, the fate that we regret to observe has overtaken the 
apparatus section, except, indeed, so far as concerns the trade 
stalls and a few exhibits that appear to be out of place in any of 
the existing departments. 
The most striking novelty in the Gallery is a ‘ parallax 
stereogram’””’ shown by Mr. F. E. Ives. No details are fur- 
nished, but we believe that the photograph is taken by means 
of a lens of large diameter obscured except for two apertures, 
one on each side, so that it acts ina similar way to the two 
lenses of the ordinary stereoscope camera, but that the two 
images are superimposed, In front of the sensitive plate there 
is placed a screen with vertical lines onit, alternately opaque 
and transparent, at such a distance that each image will impinge 
upon the plate in narrow, vertical strips and in the shadows of 
the opaque lines cast by the light transmitted by the other 
opening in the lens. The two images are thus received on the 
plate in narrow, alternating strips. For viewing, the eyes take 
the place of the openings in the lens, the lined screen remaining 
in position to keep the two images separate. The correct posi- 
tion for the eyes is indicated by two holes in a board, no other 
apparatus being necessary. The effect is perfect. . 
The only example of colour photography by the Lippmann 
process is a photograph of the spectrum of the arc light by Mr. 
Edgar Senior. This is an improvement on Mr. Senior’s previous 
noteworthy results, being taken with a narrower slit, but still 
the colours shown are not quite the same as those which one 
sees in the direct spectrum. It seems not unlikely that the 
differences are inherent in the process. Of other prints in 
colour, Mr. Brewerton contributes some in which the blue print 
is in Prussian blue, and the red and yellow superposed carbon 
prints, and Miss Acland some copies of miniatures by a modifi- 
cation of the Sanger Shepherd three-film process. These results 
are admirable, but they arenot convincing. It would be better 
if an object were used less valuable than a precious miniature 
and more convenient than a landscape, so that the object and the 
copy could be exhibited side by side. It is well known that 
very good results can be obtained ; we want now to see how near 
they are to perfection. 
Mr. Hort Player exhibits some splendid examples of his 
method of copying engravings by superposition. The ordinary 
relative positions of the engraving and the sensitive paper are 
reversed, the light passing through the sensitive paper before it 
lluminates the engraving. A yellow screen is used, and potass- 
NATURE 
[OcTOBER 9, 1902 
ground, the blackness of the lines and the sharpness of the 
detail are excellent. 
Photomicrography is well represented. The most notable 
examples are a series of photomicrographs taken in connection 
with the bacterial treatment of sewage, exhibited by Dr. Clowes. 
The enlargements vary from about natural size up to three 
thousand diameters. These fifty or more photographs may 
well be accepted as a model of what this kind of technical work 
should be. Mr. Ives has twelve photomicrographs made witha 
small and simple apparatus that is not described. The results 
would do credit to any apparatus, and show what may be done 
by care and skill without elaborate conveniences. Among the 
other work of this class that deserves commendation is a series 
of microphotographs of etched alloys by Mr. Earnest A. Lewis. 
Astronomical and spectroscopic photography is well repre- 
sented by very fine work from Sir Norman Lockyer, Captain 
Hills, the Greenwich Observatory and others. Some of the 
spectra have no wave-length scale attached, or any other indi- 
cation of the part of the spectrum represented, and others bear 
no indication of the facts sought in their preparation or of the 
facts that the spectra demonstrate. If a little information of 
this kind were invited by the Society’s officers and incorporated 
in the catalogue, the exhibits would gain vastly in interest. This 
want of information is also manifest in the ‘‘ multiple lightning 
flash,” fourfold, by Mr. J. Howden Wilkie, presumably taken 
with a swinging camera, and in other cases. 
There are many other exhibits that deserve more than a 
passing mention. Snow formations, huge ‘‘ caps ” and ‘‘ mush- 
rooms” are illustrated by Mr. Vaughan Cornish (see p. 453 of 
this volume). Balloon photographs, Rontgen-ray work, the 
photography of animals and meteorological photography are 
represented by collections of good and in some cases unique 
examples. 
THE BRITISH ASSOCIATION AT BELFAST. 
SECTION K. 
BOTANY. 
OPENING ADDRESS BY PROF. J. REYNOLDS GREEN, M.A., 
Sc.D., F.R.S., PRESIDENT OF THE SECTION. 
THE visits of the British Association to a particular city recur 
with a certain irregular frequency and bring with them a tempta- 
tion to the President of a Section to dwell in his opening Address . 
on the progress made in the science associated with that Section 
during the interval between such consecutive visits. This course 
possesses a certain fascination of its own, for it enables us to 
realise how far the patient investigations of years have ultimately 
led to definite advances in knowledge and to appreciate the 
difficulties that have involved disappointments, and that still 
have to be surmounted. We like to look back upon the 
struggles, to record the triumphs, to deplore the failures and to 
brace ourselves for new efforts. The opportunity afforded 
hereby for criticism of methods, for reconsideration of what 
have been held to be fundamental principles, for the laying down 
of new lines of work based upon longer experience, shows us 
how desirable such a periodical retrospect may be. 
Standing as we do almost at the threshold of a new century, 
it seems particularly advisable that we shall occupy our thoughts 
with some such considerations to-day. I do not wish, however, 
so much to dwell upon the past and to lead my hearers to rest in 
any way satisfied with the achievements of the last century, 
phenomenal as they have been, as to direct attention to the 
future and to place before you some of those problems which at 
the opening of the twentieth century we find awaiting investiga- 
tion, if not solution. 
Ican only attempt to deal with a small portion of the botanical 
field. These are the days of specialisation, and when anyone is 
said to be a botanist, the question which arises at once is, Which 
particular section of botany is he associated with? The same 
principle of subdivision which cut up the old subject of Natural 
History into Zoology, Botany and Geology has now gone further 
as knowledge has increased, and three or perhaps four depart- 
ments of botany must be recognised, each demanding as much 
study as the whole subject seemed to only fifty years ago. I 
shall therefore confine my remarks to-day to the field of vege- 
table physiology. 
I should like at the outset to recommend this section of 
ium iodide is added to the deyeloper. The whiteness of the | botanical work to those of the younger school of botanists who 
NO. 1719, VOL. 66] 
