NATURE 
[April 21, 1870 
carbonaceous matter, and flames on ignition. The four great gas- 
producing strata of New York, Pennsylvania, and Ohio thus all 
belong to the Paleozoic formation. 
THE quinquennial prize of 500ofr. of the physical and mathema- 
tical sciences of the Belgian Academy has been awarded to 
Prof. Plateau for his researches on the figures of equilibrium of a 
liquid mass without weight ; a fitting sequel to 26 years’ unre- 
mitting work, the professor being now blind. The Argenteuil 
prize of 12,000fr. has been bestowed on M. Champonnois, 
inventer of the method of distilling beet-root. 
THE Council of the Entomological Society offers two prizes, 
of the value of five guineas each, for essays, of sufficient merit, 
drawn up from personal observation in the anatomy or economy 
of any insect or insects ; the essays to be sent in before the end 
of November next, 
NOTWITHSTANDING the numerous investigations that have 
been made upon the process of gastric digestion, the ulterior 
changes that the food undergoes in the alimentary canal 
exclusive of the action of the pancreatic and biliary fluids, in 
other words, the action of the fluid secreted by the walls of 
the alimentary canal itself on the various constituents of our 
food, admitted on all hands to be considerable, has received 
but little attention. In the ‘‘ Untersuchungen aus dem Institut 
fiir Physiologie” in Graz, edited by Prof. Rollett, an essay 
appears written by Dr. Alexis Dobroslawin of St. Peters- 
burg on this subject. In order to obtain the intestinal juice, he 
made a fistulous opening into an isolated portion of the intestine 
and inserted a canular into the orifice, which was properly 
secured. The dog was fed with a pound of horse-flesh and a 
single supply of water daily. Investigations were in the first 
instance made with a view of ascertaining the quantity of intes- 
tinal secreted juice. The material obtained consisted of a thin 
fluid and of a mucous portion, the relative proportion of which 
varied to a considerable extent under different circumstances, 
but from an isolated portion of intestine (having a length of 
13 centim.) in one dog he obtained 34 grains, and in another, 
where the isolated portion of intestine had a length of 17 centim. 
28 grains per hour. The results of electrical excitation by 
means of induction currents were very similar to those 
previously obtained by Thiry, and showed a considerable 
increase in the amount of the secretion during the passage 
of the current, and further researches showed that the 
secretion thus obtained did not differ materially from that pro- 
duced in the healthy and uninjured animal by the application of 
electricity to the freshly-exposed intestinal tract. The most 
interesting part of his researches, however, bears upon the action 
of the intestinal juice on starch, albumen, and fat respectively. 
In regard to the former, he was able to convince himself, in 
opposition to the statements of Thiry, that the intestinal juice 
possesses a distinct power of converting starch into sugar, and 
this occurred in whatever state the juice might be, whether clear, 
or troubled, or filtered, or mingled with flocculent masses of 
mucus. The time required was in all instances nearly the 
same, or about two hours. In one instance, evidence of the 
presence of sugar was obtained in a quarter of an hour, In 
regard to albumen, his experiments were made with portions of 
raw fibrin of blood. These were kept at a temperature of about 
100° Fahr., in contact with some of the recently-obtained intes- 
tinal juice, and it was found that a solvent action did occur, but 
with great slowness, from twenty to forty, or even forty-eight 
hours being required. The dissolved fibrin underwent conversion 
without the development of any putrefactive odour into peptones, 
as was demonstrated by the action of a series of tests. The 
researches made with a view of ascertaining the action of the 
juice on fats, as olive oil and butter, had a negative result ; he 
was never able to discover any of the fatty acids. 
In the last part of Schultze’s “Archiv. fiir Mikroskopische-Ana- 
tomie,” M. Schwalbe describes the lymphatic spaces of the eye. 
In this paper he shows that there is a large space comparable to a 
lymphatic sac lined by nucleated epithelium, as shown by the 
action of nitrate of silver situated between the choroid and 
sclerotic coats. When injected with a coloured fluid the injec- 
tion escapes from the globe by channels surrounding the venze 
vorticosee, and then distends the space known as the capsule 
of Tenon, From thence the fluid passes backwards through a 
sheath surrounding the optic nerve, and so penetrates into the 
arachnoid space of the brain. 
THE Rey. W. P. Clarke, vice-president of the Royal 
Society of New South Wales, sends us an interesting paper 
on the Causes and Phenomena of Earthquakes, especially in 
relation to shocks felt in New South Wales and in other 
provinces of Australasia. 
In a letter to Hardwicke’s Science Gossip, Mr. W. W. Spicer 
states that the colour of insects is greatly influenced by the length 
of time during which they have remained in the chrysalis condi- 
tion, well-marked varieties being produced by preserving the 
chrysalis in a state of abnormal torpidity through the autumn and 
winter, which can be done by keeping it in ice. 
THOSE of our readers who are interested in the theory of 
vision will find an instructive paper by Mr. G. Joseph Towne, 
in the last issued volume of the ‘‘Guy’s Hospital Reports” (1870). 
It deals chiefly with the subject of binocular vision, with a 
criticism on the views recently promulgated by Professors Hering 
and Helmholtz, and at the conclusion of his essay he makes the 
following statements :— ‘‘ That the images of all objects placed 
within the transverse visual plane are referred to the opposite 
side of the field; that is, to the side of the field opposite to that 
occupied by the object viewed, and we remark that this pheno- 
menon is special to the transverse visual plane. That in select- 
ing the transverse visual plane as the region for his experiments, 
and in haying applied to the field generally the exceptional 
phenomena special to this region, Hering has committed an 
error, which is fatal alike to the consistency of his experiments 
and to the soundness of his conclusions.. That the phenomena 
on which Hering has based his theory are inseparably con- 
nected with anear convergence of the eyes, and it may be asserted 
that similar phenomena cannot occur, the field being viewed 
with the optic-axes parallel.” Mr. Towne’s statements are 
supported by much ingenious reasoning, and references to 
numerous experiments, some of which are illustrated. 
LarcE beds of rock-salt have been discovered by borings, 
in the neighbourhood of Middlesborough-on-Tees, and shafts 
are now being sunk with a view to work the valuable deposits. 
In this we have another example of the mineral character of 
that north-east corner of Yorkshire. Iron ore and smelting 
furnaces abound. Mineral waters well-up in sundry places. 
Alum used to be made at Guisborough, near the foot of Rose- 
bury Topping ; and now the rock-salt offers a new resource to a 
large and busy port, which, forty years ago, was a wild waste 
with two or three houses only. 
Ir is perhaps a sign of a wider awakening interest in 
geology among the Italians, that a new journal—Zolletino R. 
Comitato Geologico d’Ttalia—was brought out at Florence, at 
the beginning of the present year. The second number has 
just appeared, It contains papers and notices on geological 
and mineralogical subjects, illustrated by engravings, and so 
far fulfils its purpose of making ‘‘ better known than hitherto 
the geology and topography of Italy.” We are glad to welcome 
this new periodical; for the more the Italians become 
acquainted with the natural resources of their country, the 
better will it be for all concerned, 
