diabetes. In none of them, however, did indications of saccharine matter appear. In one instance, indeed, there was a degree of blackness, such as might have been occasioned by the addition of about one grain and a half of sugar to an ounce of serum; but this matter did not exhibit the properties of sugar it was more easily dried, had a greater refrac tive power, and was not fusible by heat. The addition of a proportion of diabetic urine, not exceeding one half, occasioned the colour of the drop after evaporation to be darker, and the chrystallization of the salts to be more defective.

As the existence of sugar in the blood of diabetic persons seems to be disproved by these experiments, it is evident, either that it must be secreted in such cases by the kidneys, or, formed in the stomach, conveyed from thence to the bladder by some unknown channel. And that some such secret communication does actually exist between these organs, is rendered highly probable by further experiments of Dr. Wollaston. Having ascertained that the prussiat of potash might be taken without injury, three successive doses of three grains and a half each were administered to a healthy person, at intervals of an hour each. The urine was tinged in two hours, and at the end of four hours afforded a deep blue colour; but the serum of the blood drawn at the same period, when examined by the appropriate tests, gave no signs of the prussiate. Dr. W. also examined the salivary secretion repeatedly, and the mucus of the nostril when secreted in excess from the influence of catarrb-but without being able to detect in either the slightest trace of prussic acid, while the urine, at the time, contained it in considerable abundance,

A Letter from Dr. Marcet is appended to this Paper, containing an account of several experiments which he made on this subject at the instance of Dr. W. He gave to a young woman labouring under diabetes mellitus, five grains of the prussiat of potash every hour, for thirteen successive hours. After the fifth dose the urine became instantly blue, on the addition of a drop or two of a solution of sulphat of iron. At this period a blister was applied on the region of the stomach, and while she continued taking the prussiat the serum was collected and examined; but it gave no indication of the presence of prussic acid, though the urine was sensibly impregnated with it fifteen hours after taking the last dose. The urine of the same person, after having taken considerable quantities of sulphat of iron, gave no signs of its presence when tested by the prussiat of potash. In a third experiment, the blood of a young woman, who had taken a dram of the prussiat in about twelve hours, was found to contain no vestige of prussic acid in its serum, though the urine was

strongly impregnated with it during the six hours which ceded and followed the experiment.

pre

VI. On the rectification of the hyperbola by means of two ellipses; proving that method to be circuitous, and such as requires much more calculation than is requisite by an appropriate theorem: in which process a new theorem for the rectification of that curve is discovered.To which are added some further observations on the rectification of the hyperbola: among which the great advantage of descending series over ascending series, in many cases, is clearly shewn; and several methods are given for computing the constant quantity by which those series differ from each other. By the Rev. John Hellins, B.D. F.R.S. and Vicar of Potter's Bury, in Northamptonshire.

This is a useful, though, we think, rather tedious paper. Some of the blunders of Mr. Woodhouse, and some of the excellencies of Maclaurin, Simpson, and Landen, when investigating kindred subjects, are pointed out. The new theorem referred to in the title of the paper, is this: H

eV

G, where H denotes the hyperbolic arc, e✔l + bb, 2 and 2 b being the transverse and conjugate axes of the ellipse, x the abscissa measured from the centre on the transverse axis, and y the corresponding ordinate, e = quantity eV being purely algebraic, and equal to eu that is, eux, and the other quantity G = e

-uu

x the fluent of "√ (1 — uu)

E

1; the

Where it is evident that the

computation of this latter term is not more laborious than the usual process for the determination of an elliptic arc.

VII. On a combination of Oxymuriatic Gas and Oxygene Gas. By Humphry Davy, Esq. LL. D. Sec. R. S. Prof. Chem. R. I. Read February 21, 1811.

The gas described in this paper has probably given rise to much of the confusion and uncertainty which has prevailed relative to the hyper oxymuriates, from which it is obtained by the agency of muriatic acid. As its properties, however, vary with the proportions of acid and salt, it is necessary that the salt should be in considerable excess, and the acid a good deal diluted with water. It must be collected, too, over mercury, as water absorbs it pretty freely, and until it is saturated or nearly so, nothing but oxymuriatic gas is obtained. Its colour is a dense yellow green. It explodes even with the warmth of the hand, and often while transferring from one vessel to another, with heat and light and expansion of volume. The result of its spontaneous explosion is the disengagement of from

to

1

of oxygene, its vivid colour disappears, and it is converted into oxymuriatic gas. It is, therefore, evidently a compound of oxymuriatic gas and oxygene mixed with some of the former gas. By agitating it with mercury, the free oxymuriatic gas combines with the mercury, and forms corrosive sublimate, leaving the gas pure. In this state it is so easily decomposed as to make it dangerous to operate upon large quantities. When exploded over mercury, 50 parts expand to 60; and the oxymuriatic gas being absorbed by water, there remains 20 parts of pure oxygene gas; so that it consists of 2 in volume of oxymuriatic gas and I of oxygene, the oxygene being condensed to half its volume by combination. The smell of the pure gas resembles that of burnt sugar, mixed with that of oxymuriatic gas. Water absorbs eight or ten times its volume of it, and acquires a colour approaching to orange. Detonated with twice its volume of hydrogene, there is an absorption of more than; and a solution of muriatic acid is formed: but when the explosive gas is in excess, oxygene is always expelled,a fact which Dr. D. regards as proof of the affinity of hydrogene, for oxymuriatic gas, being stronger than for oxygene. Mercury, copper, antimony, arsenic, and iron, did not inflame in it, until the gas had been made to explode, when they burnt with different degrees of brilliancy, and combined with the oxygene or oxymuriatic gas according to their respective affinities. Both nitrous and muriatic acid gas decompose it, the former with diminution of volume and the production of red fumes, and the latter with the formation of oxymuriatic acid, and the appearance of dewy moisture on the sides of the vessel, and with rapid diminution of volume on the application of heat. This gas destroys dry vegetable colours, but previously gives them a red tint,-a circumstance which, joined to its affinity for water, inclines Dr. D. to adopt the opinion of Chenevix, that it is allied to the acids in its nature and he thinks it is probably combined with the peroxide of potassium in the hy per-oxymuriate of that metal. The very feeble affinity which exists betwixt the oxymuriatic gas and oxygene, and the singular phænomena which attend their separation, certainly fayour the conclusion that they are analogous species of matter: And we cannot but think that the views of Dr. D. relative to the oxymuriatic acid, are strongly supported by the nature and properties of this extraordinary compound-for which, from its colour and its relation to the oxymuriatic gas, he proposes the name of euchlorine, or euchloric gas.

VIII. Experiments to prove that fluids pass directly from the stomach to the circulation of the blood, and from thence into the cells of the spleen, the gall bladder, and urinary bladder, with

out going through the thoracic duct. By Everard Home, Esq. F. R. S. Read January 31, 1811.

We are glad to find that Mr. Home has abandoned his former speculations on the use of the spleen in the animal economy; though we feel considerable regret that his erroneous conclusions should have led to the repetition of experiments, incalculably painful to the unfortunate animals that were the subjects of them, and which do not appear likely to lead to any very useful or important conclusion. The present experiments, which are five in number, prove, indeed, that fluids may pass from the stomach to the urinary bladder and some of the neighbouring organs, without passing through the thoracic duct; but there is no evidence adduced whatever, that, in order to arrive there, they must have been conveyed through the circulating system, except a reference to Mr. Home's former experiments, from which it appeared that the blood in the splenic vein was tinged with rhubarb which had been introduced into the stomach. In the two first experiments described in this paper, a ligature was passed round the thoracic duct so as to render it quite impervious, and two ounces of a strong infusion of rhubarb was then injected into the stomach. In three quarters of an hour, the urine was tested by potash and found to contain rhubarb, and in one the bile also exhibited similar appearances to the same test. third experiment was varied, by the previous extirpation of the spleen four days before the experiment was made: but the rhubaib still made its way to the bladder, so that the spleen could have nothing to do with its conveyance thither. In the fourth and fifth experiments, not only the thoracic duct but also the lymphatic trunk which terminates in the angle betwixt the right jugular and subclavian veins, was secured by a ligature. The results, however, were similar to those of the former experiments; both the urine and bile being impregnated with rhubarb in the last, a portion of the spleen infused in water afforded similar indications though not equally strong. In several of the experiments, the thoracic duct burst in consequence of the ligature, but the chyle gave no indication of its containing rhubarb.

The

As the spleen is thus demonstrated not to be an organ intended for the mere conveyance of fluids from the stomach to the bladder, Mr. Home fancies that it must be a secreting organ, that the rhubarb is deposited in the cells in the form of a secretion.' The arguments adduced in support of this opinion do not, however, amount to any high degree of probability, much less to satisfactory proof. As all other secreting glands have excretory ducts, analogy is clearly against it; and we think this of much greater weight than the mere size

and number of the lymphatic vessels of the spleen, or the greater abundance of fluid in its cells during the process of digestion. Mr. Home observes, indeed, that, where a secretion is to be carried into the thoracic duct, it would be a deviation from the general plan of the animal economy, were any but lymphatic vessels employed for that purpose:' but this is nothing better than a petitio principii; since it is not known that any secreted fluids, except chyle and lymph, are conveyed to the thoracic duct.

IX. On the composition of Zeolite. By James Smithson, Esq. F. R. S. Read February 7, 1811.

Zeolite, has been considered, hitherto, a perfectly distinct species of mineral from natrolite, in consequence of Vauque. lin having found a considerable proportion of lime, but no fixed alcali, in some of the former, while Klaproth had obtained soda, but no lime, in his analysis of the latter. And though this latter mineral has recently been found in chrystals, having exactly the same form as zeolite, yet the acknowledged accuracy of those distinguished chemists prevented Haüy from uniting them under the same species.

Mr. Smithson had formerly obtained soda from zeolites which he had collected on the island of Staffa, and procured from other situations and having lately received some minerals from Haüy, he has at length had an opportunity of analyzing a specimen, marked by that celebrated mineralogist, and bearing the same name (mesotype) with that analyzed by Vauquelin. Ten grains of it gave 4.90 silica, 2.70 alumine, 1.70 soda, and .95 water; an estimate which exceeds the original weight by .25, but which is sufficiently accurate to determine the close affinity of this substance to natrolite.-Mr. Smithson, however, appears to exult in the superior accuracy of chemical analysis, without sufficient reason; since it is evident that the perfect similarity of their chrystalline forms would have led Haüy to class them together, if he had not been withheld by deference to the authority of Klaproth and Vauquelin.

X. Experiments and observations on the different modes in which death is produced by certain vegetable poisons. By B. C. Brodie, Esq. F.R.S. Communicated by the Society for promoting the Knowledge of Animal Chemistry. Read February

21, 1811.

Mr. Brodie states it to have been the principal aim of these experiments, to determine on which of the vital organs the poison employed exercises its primary influence, and through what medium that organ becomes affected.'

In the first series, alcohol, the essential oil of bitter almonds, the expressed juice of the leaves of aconite, infusion of to