May 22, 1902] 
NATURE 
83 
far as we can judge, to be a really useful compilation. It 
gives great masses of very varied data about all sorts 
of examinations; contains an excellent “Calendar of 
Examinations” and much general information such as 
masters and their pupils need, and it is provided with a 
useful index. 
THE ROYAL SOCIETY CONVERSAZIONE. 
A LARGE number of exhibits of scientific interest 
were on view at the conversazione of the Royal 
Society, held on Wednesday of last week. Following 
our usual course, we give a list and brief descriptions of 
the objects exhibited, abridged from the official 
catalogue :— 
The Badische Anilin and Soda Fabrik, Ludwigshafen on the 
Rhine, had an exhibit of synthetic indigo, consisting of (a) 
specimens of the raw material (naphthalene) and the intermediate 
products formed in the manufacture of synthetic indigo, as well 
as of the latter in four different forms; (4) examples of various 
textile materials illustrating the application of synthetic indigo 
on loose wool, slubbing, military cloths of different nations, 
attention to the desirability of having similar models made of 
the British breeds of horses and cattle. 
Newly discovered fossil mammals and reptiles from Egypt 
were’also exhibited by the director of the British Museum (Natural! 
History). The principal mammalian remains exhibited were 
those of Mceritherium and Palzomastodon, from the Upper 
Eocene and Oligocene respectively, which seem to be the oldest 
known ancestral Proboscidea. Mceritherium is a comparatively 
small animal, still retaining the canines and all the incisor teeth: 
in the upper jaw, though the second pair of incisors is much 
enlarged. Palzeomastodon has nearly reached the stage of 
dentition known in Mastodon, but more teeth are simultaneously 
in use, and the third molar is simpler than in the latter. Bary- 
therium, represented by a mandible and part of the upper jaw, is- 
a large and massive animal of uncertain affinities. The vertebree 
named Gigantophis indicate the largest known snake, probably 
50 feet in length. 
On behalf of Colonel Sir Edmund Antrobus, Bart., Mr. W. 
Gowland showed a number of stone implements, &c., from 
Stonehenge. 
On behalf of Miss Breton, the Rev. H. H. Winwood showed 
some striking water-colour sketches, executed by her, of cafions, 
glaciers and waterfalls in the United States and British Columbia, 
illustrating effects of various agents in land-sculpture. 
Mr. T. Andrews, F.R.S., exhibited photomicrographs of the 
| erystalline structure of platinum and of the crystalline structure 
cops, cross-reeled bundles, cotton piece goods both dyed and | 
printed. 
Mr. R. L. Mond and Dr. M. Wilderman exhibited a new 
and improved type of chronograph, in which, instead of moving 
the heavy drum, the clock moves a very light spindle carrying 
the writing pen round the drum. 
Dr. J. Mackenzie Davidson showed (1) stereoscopic X-ray 
transparencies and negatives in a Wheatstone stereoscope and 
in a revolving stereoscope ; (2) X-ray photographs of a bullet 
fired from a revolver. Dr. Davidson also demonstrated that if 
an ordinary photographic plate be exposed to X-rays and then 
to ordinary diffused actinic light, a reversed negative is obtained 
on development in bright white light. 
An improved form of Thomson coal-calorimeter was exhibited 
by Mr. W. Rosenhain. 
Apparatus for natural colour photography, and examples of 
its applications, were shown by Messrs. Sanger Shepherd and 
Co., who also exhibited a new camera for securing the three 
negatives through one lens at one exposure, and a camera for 
photomicrographic work fitted with colour filters for natural 
colour photography. 
By means of a three-circle goniometer exhibited by Mr. G. F. 
Herbert Smith, the determination of the symmetry and the 
interfacial angles of crystals is considerably simplified; the 
crystal needs to be only once adjusted for the whole series of 
observations. By means of the particular optical arrangements 
in this instrument, measurements may be made through more 
than 180° across the end of the crystal by rotation of the hori- 
zontal circle only. ; 
The Department of Applied Mathematics, University College, 
London, showed (1) a curve-adder, made by G. Coradi, of 
Ziirich, for Prof. K. Pearson,.F.R.S.; (2) lecture models, 
illustrating graphical treatment of girder-deflections; (3) a 
circular slide rule and planosphere, made about 1670, the former 
on Oughtred’s system; (4) a slide rule, designed by Prof. 
de Morgan, and believed by him to be first circular slide rule. 
Notabilia of Gilbert of Colchester were exhibited by Prof. 
S. P. Thompson, F.R.S. 
Prof. G. Forbes, F.R.S., showed his folding range-finder, 
which has already been described in these columns. 
Mr, J. Stanley Gardiner showed photographs of natives of | 
the Maldive Archipelago, and photographs of the coral reefs. 
Coloured sketches of birds and fishes obtained during the 
voyage of the Discovery to New Zealand were exhibited by 
Mr. E. A. Wilson. 
Mr. J. Gray exhibited cephalometric instruments and cephalo- 
grams specially designed for measuring and taking contours of 
the living head. 
of large steel ingots. Prof. A. H. Church, F.R.S., showed 
series of zircons from Ceylon, illustrating range of density and 
colour. Dr. C. A. MacMunn showed (1) the spectrum of a 
zircon; and (2) spongioporphyrin, the colouring matter of 
Suberites Welsont, an Australian sponge. This name has been 
given by Prof. Ray Lankester to the above pigment. The 
pigment.gives a very remarkable absorption spectrum, recalling 
to mind that of oxyhzmoglobin, of turacin, of carminic acid, 
&e. 
Some successful attempts to reproduce polarisation effects by 
three-colour printing were shown by Prof. H. A. Miers, F.R.S. 
The pictures were collotype prints from photographs of the 
coloured interference figures produced by crystal sections in a 
polariscope. 
The experiments shown by Prof. J. A. Fleming, F.R.S., to 
illustrate the effect of ultra-violet light on the electric discharge 
attracted much attention. Effects of ultra-violet radiation were 
also shown by Dr. Dawson Turner. 
- Sir Norman Lockyer, K.C.B., F.R.S., showed (1) metallic 
spark spectra in air and water. Photographs of spark 
discharges from poles of iron, magnesium, zinc and copper show- 
ing (a) broadened bright lines, (4) broadened bright lines with 
central absorption, and (c) broadened bright lines with non- 
symmetrical absorption (maximum of -emission towards red) ; 
(2) spectra of meteorites on silver poles, showing the varying 
intensity of lines due to special constituents ; (3) spectra of 
rocks and minerals on silver poles, showing distribution of 
vanadium, titanium, chromium, &c. ; (4) spectra of plant ashes 
on silver poles. 
A new temperature indicator (Whipple’s) was shown by the 
Cambridge Scientific Instrument Company. This instrument 
is intended for use with a platinum resistance thermometer. 
The bridge-wire is wound on a cylinder in the form of a screw, 
and the sliding contact is moved until the resistance of the 
thermometer is balanced. 
Mr. C. E. Stromeyer gave an experimental illustration of 
one cause of steam-pipe explosions. 
A new and very effective electrical influence machine suitable 
for campaign work with Réntgen rays was shown by Mr. W. R. 
Pidgeon. 
One of the most novel exhibits was a large prism of vitreous 
silica shown by Mr. W, A. Shenstone, F.R.S., and Mr. J. W. 
Gifford. The employment of vitreous silica in optical work has 
| been delayed by the impossibility of building up very large and 
The director of the British Museum (Natural History) showed | 
(1) models of deep-sea fishes (Gastrostomus bairdi and Sacco- 
pharynx flagellum) ; (2) three statuettes of horses and one of a 
Hungarian bull, one-fourth natural size, by G. Vastagh, of 
Buda-Pesth. These were exhibited with a view to direct 
NO. 1699, VOL. 66] 
perfectly homogeneous masses of the material in the oxy-hydrogen 
flame. But this difficulty has now been overcome to a great 
extent. 
Prof. Wyndham R. Dunstan, F.R.S., director of the scientific 
department of the Imperial Institute, exhibited (1) poisonous 
fodder-plants and food-grains, and their cyanogenetic glucosides. 
These illustrate an investigation of the cause of the hitherto 
obscure poisonous action of certain Indian and Colonial fodder- 
plants and food-grains. The plants shown have now been proved: 
to furnish prussic (hydrocyanic) acid, and in the cases of 
