absence of these two acids in any sensible quantity, and still further confirming the results as before obtained.

In this manner the three following results, selected from a variety of others of a similar nature, were obtained,

These results then seem to demonstrate, that free, or at least unsaturated muriatic acid in no small quantity exists in the stomach of these animals during the digestive process; and I have ascertained, in a general manner, that the same is the case in the stomach of the hare, the horse, the calf, and the dog. I have also uniformly found free muriatic acid in great abundance in the acid fluid ejected from the human stomach in severe cases of dyspepsia, as the following examples show. The original quantities of the fluids operated on of course were various, but for the sake of comparison they are reduced, in the following table, to one pint, or 16 fluid ounces, which quantity, in three instances (selected from many others), was found to contain of

No. 1, No. 2. No. 3. grs. grs. grs.

Muriatic acid in union with a fixed alkali....12·11 12.0 11.25

with ammoniat

in a free or unsaturated state

0.0 0.0 5.39

5.13 4.63 4.28

Total 17.24 17.03 20.92

ARTICLE XI.

On the Arrangement of Papilionida. By J. E. Gray, MGS. (To the Editors of the Annals of Philosophy.)

GENTLEMEN,

July 7, 1824. MR. F. CUVIER has observed that sufficient attention has not been paid by modern naturalists to the works of Linneus, and

For the sake of analogy, the chlorine, in union with the basis of the fixed alkali, is reduced in this table and the following to the state of muriatic acid.

+ I have never in more than one instance (No. 3, of the above table) been able to detect any sensible quantity of the muriate of ammonia in the fluids ejected from the human stomach; and upon inquiry of Sir Astley Cooper, who was kind enough to furnish me with the fluid for examination, I was informed that the patient was in the habit of frequently taking ammonia as a medicine.

there is a great deal of truth in this remark; for it is too much the fashion to abuse without consulting them. The fact is indeed fully verified in the butterflies which Linneus divides into five groups, the Equites, Heliconii, Danai, Nymphales, and the Phebeji, which could only have taken place by his secretly observing their habits, according to his own maxim, for his characters are only taken from their size, colour, and the difference of the edge of the wing. Latreille has divided this family from their manners and habits into exactly equivalent groups, only placing the Danai between the Equites and the Heliconii, and placing the second section of the Plebeji in a family by themselves under the names of Hesperiada.

I have observed that whenever a group formed a good linear series, the two ends would meet, and thus form a circle, by which fact I have convinced several persons who have been disposed to doubt the truth of the circular disposition of nature. Thus we find that several series forms circles which their authors never appeared to have the slightest idea of. It is so with the slight alteration proposed by Latreille with regard to the Papilionida; and the Linnean position of the Heliconii in them is similar to his position of the Cetacea in Mammalia; it prevented the continuance of the series, and thus obscured their natural disposition.

In the Equites and the Danai, the larvæ are long and cylindrical, and the chrysalis is angular, and inclosed in a kind of case, or suspended by a transverse thread; in the former of these, the lower pair of wings are generally extended at their hinder angles into a tail, in the males at least, and in both they are furnished with a connecting nerve. From the latter of these groups by means of some of the Pontia of Fabricius as P. sinapis, we pass to the Heliconii and the Nymphales, in both of which the chrysales are suspended without any case by their hinder extremity, and their front pair of legs are folded up, in the males at least, so as to be useless in walking, and the lower pair of wings, like the Danai, are usually destitute of tails and connecting nerve. From these last, by means of the genus Libithea of Fabricius, we pass to the Plebeji, where the larva and pupa are short, and the latter is inclosed in a case, and where the lower wings are destitute of any connecting nerve, but are often provided with several tails; from these we may return to the Equites, for this last group has the cased pupa and the tailed wings of that tribe, and some of them appear to have a very great affinity to it.

The Hesperiada has very great affinity to the Plebeji, of which Linneus regarded them as a section, but I am inclined to consider them as the osculant group between the Papilionida and the Spingida, excluding from it the genus Urania, which appears to be the osculant on the other side between the Papilionida and the day-flying Phalanida, but adding to the Hesperiade the genera Castnia of Latreille, and Agarista of Leach.

ARTICLE XII.

On the Results of some Chemical Analyses, and the Decomposition of Silica.* In an Extract of a Letter from M. Berzelius to M. Dulong.†

...I HAVE undertaken some experiments on uranium, in order to determine certain points which M. Arfwedson had left undecided in his excellent memoir on that metal. You are probably unacquainted with that work, though it well deserves to be known. Arfwedson has found the means of obtaining metallic uranium; he has studied its properties, and determined the composition of its oxides. With respect to the yellow oxide, however, his results are not always invariable. I have resumed the inquiry, and have completed the analysis of the uranite of Autun, which I find is a double subphosphate of lime and yellow oxide of uranium. It contains, besides, the phosphates of barytes, magnesia, manganese and ammonia. The green uranite from Cornwall is a similar compound, except that the lime is replaced by an equal number of atoms of oxide of copper. It is, therefore, a double subphosphate of copper and uranium, isomorphous, but not identical with the uranite from Autun.

I have examined the combinations of acetic acid with oxide of copper, in consequence of the analyses of those compounds published by Mr. Phillips. I have found no less than five different acetates of deutoxide of copper, in which the multiples of the base are, 1, 1, 2, 3, and 72‡; the third is the blue verdigris; but as it is decomposed either by cold water, or by a heat of 60° centigrade (140° Fahr.), I consider it to be composed of neutral acetate, and hydrate of copper. You will see the reasons which have induced me to form this conclusion more fully stated when you receive my memoir.

During the last six months I have been occupied on a great work on fluoric acid. One part is already printed in the Memoirs of our Academy; another is finished, but not yet published. I have examined the combinations of fluoric acid with bases, and have discovered that what were taken for fluates are double salts. I have analyzed fluo-silicic gas, and its compounds with bases. They are all formed in the same manner, and contain a quantity of fluoric acid combined with the silica, equal to twice the quantity combined with the base. Fluoric acid gives analogous compounds with the acids of titanium, colum

*From the Annales de Chimie.

A letter to Sir Humphry Davy on the same subjects, from M. Berzelius, was read before the Royal Society, May 20. (See Annals of Philosophy, vol. vii. p. 458.)

A very extraordinary multiple, and probably a mistake; but so it is given in the Annales de Chimie.-C.

bium, tungsten, molybdena, chromium, selenium, antimony, and arsenic; with the hyposulphurous and sulphurous acids, and probably with the phosphorous and hypophosphorous; but I have not yet examined the latter.

Fluoric acid is one of the most convenient reagents for the analysis of inorganic substances, since it dissolves every thing that is not attacked by the other acids. It has enabled me to determine more accurately the weights of the atoms of many of those substances about which I was still in doubt. To extract alkali from minerals, it is sufficient to treat them with fluoric acid, or a mixture of fluate of lime and sulphuric acid. In attempting to reduce fluoric acid by potassium, I have succeeded in reducing silica, zirconia, and the other earths, but I have only been able to insulate silicium and zirconium. The rest decompose water with great energy. Pure silicium is incombustible, even in oxygen gas. It is not attacked by water, nitric acid, nor aqua regia, nor by caustic potash; but fluoric acid has a slight solvent action on it, particularly with the addition of nitric acid. It does not decompose saltpetre, unless in a very intense fire, but it detonates with carbonate of potash at an incipient red heat: carbonic oxide gas is disengaged, and charcoal set free, When silicium is heated with nitre, if a morsel of dry carbonate of soda be plunged into the mixture, detonation immediately ensues. By passing the vapour of sulphur over silicium heated to redness, the metal suddenly becomes incandescent. If the combination be complete, which seldom happens, the compound appears as a white earthy mass; it decomposes water with extreme rapidity, the water dissolves the silica and sulphuretted hydrogen gas is evolved. In this way we may obtain so concentrated a solution of silica in water that it thickens and coagulates during evaporation, and lets fall portions of that earth in the form of a gummy transparent mass. Siliciuret of

potassium, heated with sulphur, burns vividly, and leaves, when dissolved, pure silicium. In chlorine, silicium takes fire at a red heat, and there is formed a colourless, or slightly yellow liquid, with an odour similar to that of cyanogen, extremely volatile, and which sets with water and deposits gelatinous silica. I have not yet examined how silicium conducts electri city and heat, nor its specific gravity, &c. Nothing is easier than to procure this substance; the following is the method I have adopted :-The double fluate of silica and potash, or soda, heated nearly to redness to drive off the hygrometric water, is put into a glass tube, closed at one end. Bits of potassium are added and mixed with the powder by fusing the metal and gently rapping the tube. It is then heated by the spirit-lamp, and before it is red-hot a feeble detonation ensues and the silicium is reduced. The mass is suffered to cool, and then treated with water as long as it dissolves any thing. Hydrogen

gas is at first evolved, in consequence of siliciuret of potassium having been formed, which cannot exist in water. The washed substance is a hydruret of silicium, which, at a red heat, burns vividly in oxygen gas, although the silicium is not thereby completely oxidated; it is then heated in a covered platina crucible, the heat being slowly raised to redness. The hydrogen alone is oxidated, and the silicium is now no longer combustible in oxygen; but chlorine attacks it readily. The small portion of silica that is formed may be dissolved by fluoric acid, If silicium has not been exposed to a strong red heat, the acid dissolves it, with a slow disengagement of hydrogen. According to my synthetical experiments, silica contains 0.52 of its weight of oxygen. Zirconium is obtained by an analogous process. It is as black as charcoal, is not oxidated either by water or muriatic acid, but aqua regia and fluoric acid dissolve it; the latter with disengagement of hydrogen. It burns with extreme intensity at a slightly elevated temperature. It combines with sulphur. Its sulphuret is chesnut-brown like silicium, insoluble in muriatic acid and the alkalies. It burns brilliantly, and the products are sulphurous acid gas and zirconia.

ARTICLE XIII.

On the Mineral Waters of Carlsbad. By Jac. Berzelius.* CARLSBAD is situated in a deep and very narrow valley, not far from the place where the latter terminates in the valley of the river Eger. Through the middle of this spot, there flows the little river Tepel, on both of whose banks, and within a short distance from one another, the hot springs first issue from the earth. The springs themselves are extremely numerous, but those resorted to by the strangers at Carlsbad are only the following the Sprudel, the Hygeian spring, the Mill spring (Mühlbrunn), the New spring (Neubrunn), the Empress Theresa's spring (Theresienbrunn), St. Bernard's spring (Bernhardsbrunn), and, but much seldomer than the others, the Hospital spring (Spitalsbrunn). All of them issue from a species of limestone, and into each of the outlets there has been inserted an artificial pipe, through which the water, impelled by the internal pressure, is thrown up into the air in an uninterrupted jet, in a manner very convenient for those who drink it. This limestone is formed by the water itself; for the latter, in proportion as it loses carbonic acid, is incessantly depositing a concretion of a compact and crystalline texture, on every substance with which it comes in contact.

* Abridged from the Kongl, Vet, Acad, Handl. 1822, p. 139.