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lected, are too scanty to authorize any general deductions on an inquiry so extremely obscure. Mr. C. justly remarks that it
is not altogether vain to expect, that more profound views, and more applicable facts, await the researches of men, who have as yet only begun to explore this branch of natural history, by subjecting it to physical rules.'
Experiments and Observations on the Influence of the
Nerves of the Eighth Pair, on the Secretions of the Stomach. By B, C. Brodie, Esq. F. R.S. Communicated by the Society for the Promotion of Animal Chemistry.
The prosecution of the inquiry into the influence of the nervous system on the secretions of the animal economy, has been found to be obstructed by almost insufferable difficulties; and with reference to the nerves of the stomach, the death of the animal has generally occurred too early after the division of the nerves, to allow time for ascertaining its effect on the gastric secretions. As, however, the action of arsenic on the animal economy, occasions a very copious and almost immediate secretion of mucous in the stomach, Mr. B. thought it might-afford some illustration of this subject, to ascertain the effect which the division of the nerves of the eighth pair might have in an animal to whom this poison was applied. Four experiments were made, and the arsenic was applied immediately after the division of the nerves, either directly to the stomach, or to some other part of the body, ' In either case, the effect would have been a copious secretion of mucous into the stomach, had the animal been entire ; but in the animals subjected to these experiments, though the poison produced death in a few honrs, the stomach presented no appearance of unusual or unnatural secretion; nor had any been discharged by vomiting or otherwise during the life of the animal, though the mucous membrane was much inflamed. This result is certainly strongly in favour of the opinion, that the secretions are greatly under the control of the nervous power.
On a Fossil Human Skeleton from Guadaloupe. By
Charles Konig, Esq. F. R. S... The block in which these human bones, improperly denominated a fossil remain, are imbedded, was brought from Guadaloupe by Sir Alexander Cochrane. It is about a foot and a half in thickness, of a flattened oval figure, and weighing nearly two tons. The whole has very much the appearance of a huge nodule, which had been disengaged from a surrounding mass.
From notices by General Ernouf, in the Annales de Museum for 1805, and by M. Lavaisse in his Voyage à la Trinidad, Vol. V. N. S.
published in 1813, it appears, that these remains exist on a portion of the windward side of the Grande-Terre called La Moule. The situation of this skeleton in the block, is so very superficial, that Mr. K. thinks it probable its existence may have been indicated in the rock on the coast, by the projection of some portion of the bones of the left fore arm. He has given a very circumstantial account of the skeleton; and has accompanied it with an engraving, which conveys a still better idea than any description can do of its natural appearance and situation,.in relation to the block in which it is imbedded.
The skull is entirely wanting, which is the more to be regretted, as its form might possibly have led to some probable conclusion as to the peculiar race to which the individual belonged. The profound researches of Cuvier, have conferred a high degree of importance on the study of the organic remains of former ages, since by connecting them with geology, he has proved how precious are the elucidations which tbey afford of the history of the globe. In this point of view, the skeleton described in this paper, though it has proved on examination to be only an incrustation, possesses a peculiar interest, as it is, we believe, the only example which has yet been observed, of human remains occurring in any of the strata of the globe. The rock in which it was found, is calcarious; but the information on this subject is too scanty and imperfect to afford a basis for any very positive concluseons as to its probable age; and until the geological structure of the West Indian Islands shall have been more carefully studied, any attempt to assign its probable date would be premature and unsatisfactory.
Observations on the Functions of the Brain By Sir
Everard Home, Bart. F. R. S. , This paper exhibits a highly philosophical attempt to elucidate the physiology of the brain, by an attentive study of its pathology; and it is, perhaps, the only means which affords a reasonable prospect of our ever arriving at any safe and satisfactory conclusions, relative to functions of any particular portions of this most important organ. In this point of view, every injury done to the structure of the brain, either by accident or disease, may be considered as an experiment made upon it, and a careful observation of the derangements produced on the functions of the nervous system during life, connected with a minute and accurate examination of the parts after death, may ultimately lead to conclusions which may enable us to assign to each individual part, its appropriate function in the animal economy.
As the commencement of such an investigation, this paper is curious and valuable. It contains the results of the observa
tions which the Author's opportunities have enabled 'hin to collect, and we hope it will stimulate others to preserve and communícate similar records of cases which come under their notice. We frankly confess our inability to do justice to the communication, by any abstract which our limits would allow, and we shall, therefore, merely transcribe the heads or sections under which the observations are classed. These are—the effects produced by an undue pressure of water upon the brain-by concussionby the preternatural dilatation or disease of blood vessels----by the extravasation of blood-by the formation of pus-by the depression and thickening of different portions of the skull—by the pressure of tumours-by injury done to the substance of the brain-by alterations of structure from disease--and by injury done to the spinal marrow.
Further Experiments and Observations on Iodine. By
Sir H. Davy, LL. D. F.R.S. V.P.R.I. This paper contains some additional observations on the triple compounds containing iodine and oxygen, which are analogous to the hyperoxymuriates ; on the hydroionic acid, and its compounds; on the other acid compounds of icdine; on the action of some compound gases upon it, and on the means of detecting it in its combinations; and on certain properties of its combination with sodium.
In order to obtain the triple combination of iodine and oxygen, with the fixed alkalies, it is necessary to boil the products repeatedly in small quantities of alcohol, of specific gravity from 8. 6 to 9. 2, the binary combination of iodine with the alkali is thus removed, as the alcohol dissolves it readily, but has very little action on the triple compound. The experiments of Sir H. were made with the triple compound of potassium, as being most easily procured; but the properties of that with a base of sodium appear to be precisely analogous. When pure, it is nearly tasteless; it has no action on vegetable colours; is scarcely soluble in cold water ; but more so in that which is made hot; and when thrown into concentrated sulphuric, nitric, or phosphoric acids, it has no violent action upon them ; but aided by heat, it is dissolved in them, and solid crystallized compounds are formed, which are intensely acid. If its coinbination with nitric acid is strongly heated, the nitric acid is driven off, and at the temperature at which it is entirely expelled, the compound itself begins to decompose, and to afford a little iodine, and a considerable proportion of oxygen. If the combination which it forms with sulphuric or phosphoric acid, is heated to the degree at which the acids are sublimed, the triple compound is itself decomposed, oxygen and iodine are separated, and acid sulphate or phosphate of potash remains. If when the combination is rendered fluid by heat, a little sugar, or other combustible matter is added to it, there is violent action, and the iodine is disen-gaged with great rapidity. The triple compound dissolves without decomposition in phosphorus acid; but when the solution is heated, the acid attracts the oxygen, the iodine is set at liberty, and phosphate of potash is formed. If it is thrown into muriatic acid, there is an effervescence, the odour of chlorine becomes evident, the liquid becomes yellow, and when evaporated it yields chlorionic acid. When the solution of hydroionic acid in water is poured upon the triple salt, iodine is instantly produced in considerable quantity. Acetic and oxalic acids dissolve the triple compound without decomposing it; but on heating the solution in oxalic acid, charcoal is deposited, and the iodine immediately appears. When it is dissolved in sulphureous acid, iodine is immediately produced, and the acid is converted into the sulphuric, and if the quantity of acid is not too large, it dissolves part of the iodine and becomes yellow.
The binary compound of iodine and potassium has no action on oxalic, acetic, sulphurous, or phosphorous acid, except it is mixed with the triple compound, when it is immediately decomposed by these acids, and the iodine is set free. The double compound in its pure state is very slowly decomposed by muriatic acid; but when a mixture of the binary and triple compound is exposed to the action of this acid, muriate of potassa is instantly formed; and if the proper proportions are used, none of the salts remain, the results being only muriate of potassa, and oxychloric acid. A mixture of the binary and triple compounds, acted upon by glacial hydrophosphoric acid, affords iodive in large quantity, but the binary compound alone yields only hydroionic acid, and Sir H. recommends this as the best mode of procuring this acid in a pure form. From a comparative estimate of several analyses, Sir H. thinks the triple compound consists of one proportion of iodine, one of potassium, and six of oxygen. He proposes for these compounds the name of oxy-iodes, the specific appellation being derived from the base to which the oxygen and iodine are united.
The best method of procuring hydroionic acid, is by the action of hydrophosphoric acid on the binary compound of iodine and potash. It is rapidly decomposed by being heated in its gaseous form, in contact with oxygene, a solution of iodine, and hydroionic acid in water being formed. It is also slowly decomposed by heat alone, affording a deep red brown, easily fusible substance, which appears to be a combination of hydroionic gas in with iodine. When the acid gas is condensed in water, it is instantly decomposed by nitric acid, iodine being precipiLated. The solution of hydroionic acid gas in water, absorbs oxygene rapidly from the atmosphere, becoming first yellow, and afterwards of a deep tawny orange colour. The absorption of oxygen is assisted by light and heat; and Sir H. thinks the: concentrated acid will probably form an eudomietrical substance superior to any which we at present possess. It is decomposed by being heated with hyperoxymuriate of potash, iodine being disengaged. It is decomposed also in solution, as well as in the. gaseous state, by all the metals with which it has been tried, except gold and platinum ; but in some cases it requires the assistance of heat. The liquid acid tarnishes silver at common temperatures, and slowly dissolves mercury when boiled upon it. It dissolves the alkaline and common earths, and forms with them compounds strikingly analogous to the salts which they form when combined with muriatic acid.
The acid formed by the combination of iodine with chlorine, is extremely volatile. It appears probable, from several experiments on the proportions in which these bodies unite to form chlorionic acid, that it consists of one proportion of iodine united to one of chlorine; but they are evidently capable of combining in different proportions. The acid formed by the sublimation of iodine in chlorine in great excess, is of a bright yellow colour; when fused it becomes of a deep orange colour, and when sublimed it forms a deep orange-coloured gas. It is still capable of uniting with much iodine when they are heated together, its colour becones consequently deeper, and they rise together in the gaseous state. The solution of the acid in water, also dissolves iodine in large quantity, so that the proportions in which they combine may admit of considerable range. The pure solution of chlorionic acid much diluted, loses its colour when agitated in contact with chlorine for some time; and in this state, when poured into solutions of the alkaline salts or alkaline earths, it causes a precipitation of substances, having the properties of the triple compounds called oxyiodes.
If the acid is in its ordinary state, or has not been rendered colourless by agitation with chlorine, at the same time that the oxyiode is thrown down when it is added to an alkaline solution, a considerable quantity of iodine is disengaged ; and if the acid solution is concentrated, it cannot be deprived of this property. It throws down a precipitate from muriate of baryta, which has all the properties of an oxyiode, and the liquid becomes at the same time very acid. The colourless acid, added to a strong solution of ammonia, occasions the precipitation of acohite powder, which detonates feebly at a low temperature, the products being iodine, and a gas which does not support combustion; with the highly coloured acid, the precipitate from a solution of ammonia is black, and detonates with much greater force, by the slightest touch or motion. It appears to