Fan. 6, 1870] 
NATURE 
271 
similar ores. Sir Charles Lyell had observed in the basalts of 
Madeira red ochreous bands, which represented old land surfaces, 
in one of which Mr. Hartog and he had discovered a leaf-bed 
containing vegetation of much the same character as that of the 
island at the presentday. Near Catania, in a recent lava-stream, 
he had seen the junction of the lava with the soil of the ancient 
gardens ; and in character the soil now under the lava resembled 
the red beds in Madeira. Mr, W. W. Smyth was on the whole 
inclined to admit the power of metamorphism to produce such 
changes as had been here effected. He commented on the ad- 
vantages of employing this Irish ore for admixture with hema- 
titic ore, on account of the abundance of alumina present. 
Possibly there had been some difference in the chemical cha- 
racter of the different flows of basalt. Mr. Evans suggested 
that the Ballypalidy beds might be the littoral deposits of a lake 
in which the pisolitic ores of the other parts of Antrim were 
deposited farther from the shore, and subsequently buried under 
a basaltic flow. Mr. Etheridge inquired whether the pisolitic 
ore had been subjected to microscopic examination, with a view 
of finding traces of organic forms, such as Gadlionella, Mr. 
Tate, in reply, defended his views as to metamorphic action. 
He thought the uniformity in thickness and character of the 
pisolitic ore band over so large an area showed that it could not 
bea lacustrine deposit. He had not as yet examined the sphe- 
roids under the microscope. 
““Notes on the Structure of Sigi//aria.” By Principal Daw- 
son, F.R.S., F.G.S., Montreal. In this paper the author criti- 
cised the statements of Mr. Carruthers on the structure of 
Sigillaria (see Q. J. G. S. xxv. p. 248). He remarked that 
Sigillaria, as evidenced by his specimens, is not coniferous ; that 
the coniferous trunks found in the Coal-formation of Nova Scotia 
do not present discigerous tissue of the same type as that of 
Sigilaria ; that no conifer has a slender woody axis surrounded 
by an enormously thick bark; that Ca/amodendron was probably 
a gymnosperm, and allied to Szgi//aria ; that although Stigmaria 
may not always show medullary rays, the distinct separation of 
the wood into wedges is an evidence of their haying existed ; 
that the difference in minute structure between Sigi//aria and 
Stigmaria involves no serious difficulty if the former be regarded 
as allied to Cycadacee ; and further, that we do not know how 
many of the Stigwariz belong to Sigi/aria proper, or Favularia, 
or to such forms as Clathraria and Letoderma, which may have 
been more nearly allied to Lefrdophloios ; that the fruit figured 
by Goldenberg as that of Svg7//aria is more probably that of 
Lepidophioios, or may be a male catkin with pollen ; and that he 
has found 77igonocarfa scattered round the trunks of Szgz//aria, 
and on the surface of the soil in which they grew. He agreed 
with Mr. Carruthers in regarding Mr. Binney’s Stg7//aria vascu- 
faris as allied to Lepidodendron. Prof. Morris thought that 
Clathraria and Lepidophlois ought to be discriminated from the 
Sigillarie, as being rather more nearly allied with cycadaceous 
plants, especially the former. He pointed out the manner in 
which certain vascular bundles communicating between the 
centre of the stem of Szgi//arza and allied genera and their bark 
might be mistaken for medullary rays. 
““ Note on some new Animal Remains from the Carboniferous 
and Devonian of Canada.” By Principal Dawson, F.R.S., 
F.G.S., Montreal. The author described the characters pre- 
sented by the lower jaw of an Amphibian, of which a cast had 
occurred in the coarse sandstone of the Coal-formation between 
Ragged Reef and the Joggins Coal-mine. It measured 6 inches 
in length ; and its surface was marked on the lower and posterior 
part with a network of ridges enclosing rounded depressions. 
The anterior part of the jaw had contained about 16 teeth, 
some of which remained in the matrix. These were stout, 
conical, and blunt, with large pulp-cavities, and about 32 longi- 
tudinal striee, corresponding to the same number of folds of den- 
tine. The author stated that this jaw resembled most closely 
those of Baphetes and Dendrerpeton, but more especially the 
former. He regarded it as distinct from Baphetes planiceps, and 
proposed for it the name of 4. minor. If distinct, this raises 
the number of species of Amphibia from the Coal-measures of 
Nova Scotia to nine. The author also noticed some insect 
remains found by him in slabs containing Sphenophyllum. They 
were referred by Mr. Scudder to the Blattarie. From the 
Devonian beds of Gaspé the author stated that he had obtained 
a small species of Cefha/aspis, the first yet detected in America. 
With it were spines of Machairacanthus and remains of some 
other fishes. At Gaspé he had also obtained a new species of 
Psilophyton, several trunks of Frototaxites, and a species of 
? 
Cyclostigma, The President objected to the term Aeftiles be- 
ing applied to Amphibia, from which they were totally distinct. 
He questioned the safety of attributing the jaw to Baphetes, of 
which no lower jaw had been previously found. Mr. Etheridge 
remarked that the Cephadasfis differed materially in its propor- 
tions from any in either the Russian or British rocks. 
“Note ona Crocodilian Skull from Kimmeridge Bay, Dorset.” 
By J. W. Hulke, F.R.S., F.G.S. The author described a large 
Steneosaurian skull in the British Museum, from Kimmeridge 
Bay, which had been previously regarded as Pliosaurian, and 
was recently identified with Dakosaurus by Mr. Davies, sen. 
From the agreement of their dimensions, and their occurrence 
near together, the author thought it probable that this skull and 
the lower jaw described by him last session belonged to the same 
individual. It differs from the Steneosaurus rostyo-minor in the 
greater stoutness of its snout, in the presence of an anterior pair 
of nasal bones prolonged into the nostril, and in the number of 
its teeth. The author proposed to name it Steneosaurus Manseli, 
after its discoverer. 
*“Note on some Teeth associated with two fragments of a 
Jaw, from Kimmeridge Bay.” By J. W. Hulke, F.R.S., F.G.S. 
The author described some small teeth associated with fragments 
of a long slender snout not unlike that of an Ichthyosaur, but 
too incomplete to be certainly identified. The teeth are peculiar 
in the great development of the cementum, which gives the base 
of the tooth the form of a small bulb, The exserted crowns are 
slightly curved, smooth, cylindrical, and pointed. The attach- 
ment to the dentary bone was probably by means of the soft 
tissues, and the teeth seem to have been seated in an open 
groove in the surface of the jaw-bone. Until additional material 
reveals the true nature of this fossil, the author proposes to place 
it alone, and to call it provisionally Huthekiodon. The follow- 
ing specimens were exhibited :—Fossils and Rock-specimens 
from Antrim ; exhibited by Ralph Tate, Esq., F.G.S. Fossils 
from Kimmeridge Bay; exhibited by J. W. Hulke, Es4., 
F.R.S. 
Photographic Society, Dec. 14, 1869.—J. Glaisher, F.R.S., 
president, in the chair. The Secretary read a paper by Dr. Van 
Monckhoven, “On anew artificial light suitable for the production 
of photographic enlargements,” of which we give the following 
abstract :—In M. Kirchhoff’s analysis of the sun, he has shown 
that there are incandescent upon the sun’s surface large quantities 
of calcium, sodium, iron, magnesium, chromium, &c. Whether 
these metals exist in a free state on the sun’s surface, or whether 
they are in the form of volatile compounds, the presence of a very 
high temperature, z.¢. combustion, would be sufficient to yield 
not only an extremely dazzling light, but also one possessed of 
considerable chemical power. These conditions actually exist in 
the sun, the chemical action of whose rays is due mainly to the 
presence of chromium, titanium,* and magnesium. The author 
has found by experiment that nearly all the metals of the alkalies 
and alkaline earths, as likewise many of the metalloids, when 
burning in oxygen, give rise to a large emission of chemical rays, 
due to the production of an oxide at a high temperature, and that the 
same phenomenon is evident when the same oxides are produced 
by the decomposition of the metallic salts in a volatilised con- 
dition at a very high temperature. Magnesium produces oxide 
of magnesium heated to whiteness by the flame. If we direct 
the jet of an oxyhydrogen lamp upon the carbonate or the chloride 
of magnesium, we produce in either case oxide of magnesium 
(magnesia) at a high temperature, and moreover obtain in both 
instances flames rich in chemical rays. So long as the salt is not 
entirely decomposed the light is sustained in all its brilliancy, but 
when nothing but magnesia remains the light loses its brightness, 
and at the same time the greater portion of its chemical activity. 
If metallic oxides (such as lime, magnesia, alumina, zirconia) 
are employed and heated by the oxyhydrogen flame to a very 
high temperature, the illumination is very brilliant ; but it is 
much less photogenic in its character than when the oxide in a 
nascent condition is produced at a high temperature, as in the 
case of chlorides, carbonates, &c. In the latter instance the 
coloured lines of the spectrum inherent to each metal may be 
observed, but not in the former, and this circumstance induces 
me to believe that the chemical action of the sun is due to the 
cause mentioned. Magnesium is well known to emit an abun- 
dance of actinic rays ; chromium is possessed of far greater 
chemical intensity, If dry hydrogen gas is passed through chloro- 
chromic acid and afterwards ignited ina current of oxygen, oxide 
* It is only recently that this metal has been discovered in the sun. 
