Beraun, and Duckau; and the other from Eypel to Laun and Saatz, small patches being scattered over this district. On the confines of Bohemia and Moravia, especially between Hohenmouth and Tribau, it is still more abundant; it forms hills many hundred feet high on the north of Tribau.

It also occurs near Brisau and Lissitz.

(F.) Basin of Swabia and Bavaria.

This basin appears to exhibit cretaceous marls and chloritose chalk, like that of Bohemia on its southern border at the foot of the Alps, e. g. south of Munich, at Berg, and near Gastein.

(To be continued.)

ARTICLE XIII.

ANALYSES OF Books.

Philosophical Transactions of the Royal Society of London, for 1823. Part I.

UPON perusing this part of the Philosophical Transactions, we find, with respect to several of the papers it contains, having already given such full reports of them as they were read before the Society, that we have little more to do in the present analysis than to refer the reader to those reports; correcting, however, as we proceed, a few slight inaccuracies in them, and supplying a few unavoidable omissions.

1. The Croonian Lecture.-Microscopical Observations on the Suspension of the Muscular Motions of the Vibrio Tritici. By Francis Bauer, Esq. FRS. FLS. and HS.-(See Annals, N. S. v. 66.)

"This minute animal, the vibrio tritici," Mr. Bauer informs us, "is the immediate cause of that destructive disease in wheat, known under the name of ear cockle, or purples, by farmers.

"On opening some of the diseased grains, I found their cavities filled with a mass of a white fibrous substance, apparently cemented together by a glutinous substance, and formed into balls, which could easily be extracted entire from the cavities of the grains, and which, when immersed in water, instantly dissolved, and displayed in the field of the microscope, hundreds of perfectly organized extremely minute worms, all which, in less than a quarter of an hour, were in lively motion."

In order to ascertain how these animals are propagated, and how they are introduced into the cavities of the young germens, the author "selected some sound grains of wheat, and placed some portions of the mass of worms in the grooves on the posterior sides of the grains, and planted them in the ground in the

month of October, 1807. Nearly all the seeds came soon up, and I took from time to time," he continues, "some of the young plants for examination, but could not perceive any effect of the inoculation, till the month of March, 1808, when, in carefully slitting open the short stalk of a young plant, I found three or four worms within it; they were in every respect the same, but they were now about two-thirds larger, as well in length as in diameter.

“On the 5th of June, I found, for the first time, some of the worms, of different sizes, within the cavities of the young ger mens; and having, in the beginning of March, found some of them in an enlarged state in the stalk, I concluded that some of the original worms, with which I had inoculated the grains of seed, had got, during the germination of the grains, into the stalk, where they became mature, and laid their numerous eggs, some of which must be carried by the circulating sap into the cavities of the then forming young germens, in which the young worms extricate themselves from these eggs; and finding their proper nourishment within the cavities of the germens, these young worms become of mature age, and lay their eggs within the cavities of these germens, which, at that period, nearly approach towards maturity; and these newly laid eggs, I consider to be the beginning of the third generation of the worms with which I had inoculated the grains planted in the ground in October, 1807.

"Towards the end of June, the germens assumed various distorted forms, and began to be filled with eggs. I extracted carefully the whole contents of one of the largest grains, and putting it into water in a watch-glass, I found, on examination under the microscope, seven large worms, all alive, bending and twisting in the water like so many small serpents."

The largest worms are more of a yellowish-white colour than the young ones, and are not so transparent; from the head, which is somewhat roundish, and furnished with a proboscis, as mentioned in our report of this lecture, they taper gradually off towards the tail, which is scarcely half the diameter of the middle of their body, and ends in an obtuse claw-like point.

"The movements of these large worms are very faint and slow; they are very seldom observed to unroll themselves entirely; they move their heads and tails faintly, but their proboscis they move constantly, extending and contracting it quickly; and when in the act of discharging their eggs, they bend the tail-piece upwards with a very quick jerk, at the passing of every egg; after having discharged all their eggs, the parent worms soon die, and in a few days they decay, and fall to pieces almost at every joint.

"The eggs come out from the orifice in strings of five or six, adhering to one another at their ends, which then appear truncated; but, in water, they soon separate, and assume an oval

form, which, in its middle, is slightly contracted. These eggs consist of an extremely thin and transparent membrane, through which the young worm can be distinctly seen; and, if attentively observed, it may be seen moving within this envelope." The eggs, after the worms have quitted them, soon shrivel and decay, and it appears that they ultimately dissolve.

"The young worms are somewhat smaller and more transparent than those which are found in the more mature grains, but in a very short time after they have mixed with the others, they cannot be distinguished from them. Those which are found in the cavities of the mature grains, are nearly all of the same size; they are from to part of an inch in length, and part of an inch in diameter. They are milk white, semi-transparent; and if viewed with the strongest magnifying power, appear annular, like the large worms, though no external indentations are observable; they appear like fine glass tubes filled with water, and containing many air bubbles in close succession, and of the same number as the rings or joints in the old worms. At both extremities (one of which is more sharply pointed than the other), there are no such divisions or joints perceptible. These extremities are each about one-eighth of the whole length of the worm; they are perfectly transparent, and appear like solid glass.

The latter end of July, the diseased grains had almost all attained their full size, and assumed a brownish tint; and about the fifth of August they were all of a dark brown colour, variously distorted, and as hard as wood. The cavities of these grains were now completely filled with young worms, and these worms were, in every respect, the same as those with which I had inoculated my first seed grains; and those specimens were now more than twelve months old, and, consequently, the grains and the worms within them were completely dry; but after soaking them in water about an hour, the worms recovered their powers of moving, and were again as lively as those which were taken from the living plants.

"The large worms, after they become dry, die, and never revive; neither can the young worms within the eggs be revived, if the eggs have been but for a moment dry before the worms have extricated themselves." Mr. Bauer found that such worms as had been kept the shortest time in water, recovered their motions soonest; "so that those," he says, "which had been examined in the plain object-glass, where only a very small quantity of water can be applied, which very soon evaporates, almost every individual worm recovered in less than a quarter of an hour; and if the water is a second time suffered soon to evaporate, the experiment may be repeated many times successfully with the same worms; but after the second or third repetition, if there is a suspension of a week or ten days at each interval, several worms do not revive, and the number of these increases at every succeeding repetition. If this ex

periment be not repeated too soon or too frequently, the worms retain their reviviscent quality much longer; the longest period of recovery, after a second suspension, I have hitherto ascer tained, was eight months.

"If the worms are kept alive in water for a week or ten days, the experiment cannot be repeated so often, but the intervals of suspension may be prolonged considerably. I made the experiment very recently with grains which were three years and ten days old, and dry. After extracting the worms from the grains, I kept them in water 35 days, and after they had again been 15 days perfectly dry, I supplied them with water, and in less than twelve hours' soaking they were again, almost every individual, in as lively motion as if they had just been taken from fresh grains of the growing plant. I had the pleasure of showing these worms, in that state, to several Members of the Society, on the 29th of September last; after that day, I preserved the same specimens 18 days, perfectly dry; when, supplying them with water, I found, in less than three hours, at least one-third of them in lively motion; but the next morning, after they had just been 16 hours in water, they were all dead. If these worms are kept in a large glass, where the water cannot evaporate, they remain alive more than three months, but then they gradually die, and become as straight as needles." The glutinous substance in which the worms are preserved must be secreted by them, "since in grains in which the worms and the fungi or smutballs exist, that portion of the cellular tissue of the young germens, where a worm has formed its nest and laid its eggs, is entirely preserved; whilst in those portions of the grains which are immediately in contact with the fungi, the cellular tissue entirely disappears, and the fungi are only enveloped by the external tunic of the young germen."

This lecture is illustrated with two engravings from microscopical drawings by the author; one representing the diseased wheat, and the other the worms themselves.

II. On Metallic Titanium. By W. H. Wollaston, MD. VPRS. (See Annals, v. 67.)

My attention," Dr. Wollaston remarks, "has been directed, by various friends, especially by Professor Buckland, who gave me the subject of my experiments, to certain very small cubes, having the lustre of burnished copper, that occasionally are found in the slag of the great iron-works at Merthyr Tydvil, in Wales, which, from their hue, have, by some persons, been imagined to be pyritical. Their colour, however, is not truly that of any sulphuret of iron that I have seen; and though the form be cubic, it is not the striated cube of common ironpyrites, which so often passes into the pentagonal dodecahedron, but similar to that of common salt; for any marks, that are to be discerned on their surfaces, appear as indented squares instead of striæ.

"Their hardness also is totally different from that of pyrites, and is such as, when combined with the preceding characters, marks a substance wholly unknown to mineralogists. By selecting a sharp angle of one of these cubes, I found that I could not only write upon the hardest steel, or upon crown glass, but could even visibly scratch a polished surface of agate on rock-crystal.

"Having broken out some of these crystals for experiment, I found them all apparently attracted by a magnet; but observing that they had still small portions of slag adherent to them, they were next digested in muriatic acid, which, by dissolving the iron from their surfaces, soon freed them from their deceptive appearance of magnetism.

"Before the blow-pipe they are utterly infusible. A continued heat oxidates them, and they become purple or red at the surface, according to the degree of oxidation, or depth to which it penetrates."

We must here add to Dr. Wollaston's statement respecting the purity of these cubes of titanium, as given in our report of this paper, that they contain no sulphur.

In considering the properties which evince that they are in a metallic state, Dr. W. observes, that when the action of nitre upon them is rapid, "heat is evidently generated, as by the combustion of other metals; but as I acted upon them in their solid state, and did not pulverise them, I did not witness what could properly be called detonation, as described by Lampadius.” To the several metals with which Dr. Wollaston was unsuccessful in his endeavours to unite one of these cubes, as already mentioned by us, we must now add lead. The following particulars form an appendix to this interesting paper.

"Since the date of this communication, the liberality of Mr. Anthony Hill, of Merthyr Tydvil, has supplied me with a larger quantity of the slag which formed the subject of my first experiments, and has enabled me to determine the specific gravity of metallic titanium to be 53. For this purpose, the vitreous part was fused with a mixture of borax and sub-carbonate of soda in about equal quantities, and was then dissolved in muriatic acid, which also removed a quantity of metallic iron, and left the titanium freed from extraneous matter. Though great part of what was thus obtained from the interior of the slag was in a pulverulent state, the quantity, which amounted to 32 grains, and displaced 6'04 of water, was sufficient to preclude any considerable error.

"I have moreover learned that metallic cubes, similar to those which I have above described and examined, were, more than 20 years since, observed in a slag at the Clyde Iron Works in Scotland; that a small quantity has also been met with at the Low Moor Iron Works, near Bradford, in Yorkshire; and at the Pidding Iron Works, near Alfreton, in Dei byshire; and that some good specimens have been obtained