any important particular from coarse-grained specimens from Rowley. It would be easy to extend the parallelism to other classes of rocks, but I will now only observe that we have here another proof of the doctrine long taught by Lyell-the uniformity and continuity of the Laws of Nature."

Professor Morris's Testimonial.—This has been at last given to the Professor. A meeting was called on the 14th of July, at the apartments of the Geological Society, Somerset House, and a very complimentary, but by no means too much so, testimonial and 600l. were presented to the Professor. We trust the Royal Society will take the lesson.

A Fossil Hydrozoon, Palæocoryne.-The remarkable fossil on which Dr. P. M. Duncan, F.R.S. and Mr. H. M. Jenkins, F.G.S., have made their remarks in the Philosophical Transactions, 1869, was obtained from the lower shales of the Carboniferous Limestone series of Ayrshire and Lanarkshire, so rich in fossil Brachiopoda, Polyzoa, Crinoidea, and Madreporaria; and was found attached to the margins of the polyzoarium of Fenestellæ, and also in a detached and more or less fragmentary condition amongst the small pieces of broken Polyzoa and Crinoid stems which compose the fossiliferous layers of the shales. The base of Palæocoryne was expanded, giving rise to a short robust and cylindrical stem fluted and punctated on its surface, and surmounted by the body of the polypite from the upper margin of which radiate a single whorl of long and slender tentacles. On the upper surface of the body, a crateriform process, with an opening on its apex, indicates the position of the mouth. Its external investment appears to have been calcareous, covering the whole of the hydrozoon, except at the opening for the mouth and the terminations of the tentacles, which had probably ciliated ends projecting beyond the periderm or polypary. This is an almost solitary instance of a hydrozoon having a hard periderm, save the recent genus Bimeria, discovered on the west coast of Ireland by Dr. T. Strethill Wright. The Zoological position of the fossil is amongst the Hydrozoa in the order Tubularidæ, and near the Eudendridæ. Two species are described and figured by the authors, Palaeocoryne Scoticum and P. radiatum.

MECHANICAL SCIENCE.

Bessemer's Steady Cabin.-Mr. Henry Bessemer has recently patented plans for the construction of cabins in sea-going passenger ships, which shall be perfectly steady, however much the ship may roll; he hopes that by this means sea-sickness may be prevented, and voyages undertaken in peace and tranquillity. Mr. Bessemer's plans, which have been worked out with the ingenuity and mechanical skill for which he is famous, only require a practical trial to prove whether or no he has really solved the difficulty, and placed it in our power to remove a serious barrier to intercourse between nations. The cabin in these plans is circular in plan, and is hung on gimbals at its centre, the point of suspension in the ship being so chosen that the cabin as a whole shall have as little vertical motion as possible. The mode of suspension secures that the floor of the cabin shall remain horizontal, but this is not enough. In so placing the cabin that the vertical motion is

practically abolished, Mr. Bessemer has made an advance in principle on all previous attempts in this direction. Mr. Bessemer is having a vessel constructed to test his plans.

Rifled Gun.-A gun now in course of construction at Woolwich is expected to prove the most powerful piece of ordnance ever produced. This is a 35-ton gun, carrying a projectile of 550 lbs. weight, propelled by a charge of 100 lbs. of powder. It is stated that this gun is expected to prove capable of penetrating a 15-inch plate, and judging from past experience it ought to be pretty nearly competent to accomplish so much. How ships are to be built capable of resisting such a projectile, if indeed that is possible, is yet to be seen.

Ventilation of Coal Mines.—Mechanical ventilation in coal mines is steadily gaining ground, on the older plan of producing a draught in the up-cast shaft by means of a furnace. Mr. D. P. Morrison recently read a paper on the subject before the North England Institute of Mining Engineers, at which he stated that in the deepest English coal mines, mechanical ventilation would show an economy of 35 to 40 per cent. over furnace ventilation. After discussing various arrangements of mechanical ventilators, he gave the preference to the Guibal centrifugal fan.

Steam Paviour.-In Paris, a steam paviour has been introduced to do the laborious work of the men with wooden rammers, whose appearance whereever a street is being relaid will be familiar to our readers. The French machine is similar in principle to a steam hammer, and is moved about when at work by a horse.

Ventilation in Railway Carriages.-Attempts are being made to secure more perfect ventilation in the carriages of the Metropolitan Railway, and to reduce the unpleasantly high temperature of the air. Experiments are being carried out on plans due to Dr. Croft, and are reported to have been successful, the anemometer showing a strong inflowing current, without any perceptible draught in the carriages.

New Ventilating Machine.-M. F. Mulhausen, a civil engineer of Brunswick, is said to have invented a new freezing and ventilating machine. The cold is produced by the expansion of previously compressed air, a process which in principle was suggested originally, we believe, by Prof. James Thomson.

Single Rail Tramway.-Mr. J. W. Addis, C.E., is experimenting in India on a new form of single rail tramway. The vehicles used in addition to the ordinary wheels have a pair of flanged wheels, one behind the other, running on the single rail, which is laid at the centre of the track. The flanged wheels are adjusted by a screw so as to take all the weight off the ordinary wheels, without lifting them much above the roadway. An experimental line has been laid, in part at an incline of 1 in 40, and along this a pair of bullocks draw a load of 3 tons. The advantages claimed for the system are-first, a very great diminution of power expended in hauling as compared with traction on common roads; secondly, that the cost of construction is only one-half that of an ordinary tramway with two lines of rails. A tramway or railway on a similar principle was, we believe, tried some time ago in France.

Rock Boring.-We learn from a letter in the Engineer, that the diamond

rock-boring machine of Messrs. Beaumont and Appleby recently drove a bore hole 84 feet, in thirty-six consecutive hours, through very hard rock, at a slate quarry near Portmadoc. A machine capable of accomplishing such a feat ought to prove of immense service both to mining and civil engineering.

The Captain.-While we write the news of the terrible catastrophe which has happened to this vessel reaches us. The Captain was the only vessel which completely exemplified the ideas which Captain Cowper Coles has so ably and so persistently urged on the Admiralty. As a mere fighting machine, she was one of the most powerful vessels afloat, if not the most powerful of any; and in her preliminary cruise she appeared to be thoroughly seaworthy. No particulars have reached us which would enable us to surmise whether she has fallen a victim to circumstances which no foresight could have provided against, or whether the catastrophe will prove that we have not yet completely mastered the problem of carrying enormously heavy armour on vessels of her class. In thinking over the peculiarities of the Captain, we cannot forget that her main characteristic, that to which her designer attached most importance, was an excessively low freeboard. Intended when first designed to have a freeboard of 8 feet only, and a height of port of 10 feet, she had actually, in consequence of alterations during construction, or for some other reason, a freeboard of only 6 feet and a height of port of 8 feet.-(Engineering, June 24.) She was therefore an extreme example of the low freeboard type of sailing vessel, for the American monitors, with a freeboard of only 16 ins., do not carry sails; and, in spite of the voyages of the Monadnock and Miantonomoh, have not yet established a position as ocean cruisers. The Monarch, designed by Mr. Reed as a sister vessel to the Captain, has a freeboard of 14 feet. In the trial cruise of the Monarch and Captain both vessels proved remarkably steady and easy in their pitching and rolling motions.

MEDICAL SCIENCE.

The First and Second Stages of Labour.-In regard to this point, a very able paper was contributed to the Royal Society by the Rev. Samuel Haughton, F.R.S. In the first stage of natural labour the involuntary muscles of the uterus contract upon the fluid contents of this organ, and possess sufficient force to dilate the mouth of the womb, and generally to rupture the membranes; and he endeavours to show, from the principles of muscular action already laid down, that the uterine muscles are sufficient, and not much more than sufficient, to complete the first stage of labour, and that they do not possess an amount of force adequate to rupture, in any case, the uterine wall itself. In the second stage of labour the irritation of the foetal head upon the wall of the vagina provokes the reflex action of the voluntary abdominal muscles, which aid powerfully the uterine muscles to complete the second stage by expelling the foetus. The amount of available additional force given out by the abdominal muscles admits of calculation, and will be found much greater than the force produced by the involuntary contractions of the womb itself.

On the Law which regulates the Relative Magnitude of the Areas of the Four Orifices of the Heart.-Dr. Herbert Davies, Senior Physician to the London Hospital, has published a very long and important paper on the above subject. It was read before the Royal Society many months since, and will require careful study. We quite think with the author, that there can be no doubt that an instrument so accurate in the adaptation of its valvular apparatus must reveal, on close examination, the existence of laws which not only determine the force required to be impressed on the blood traversing its chamber, but also the relative sizes of these apertures to one another.

What is Vaccinine?-The answer must be that it is a crystalline principle extracted from the leaves of the cowberry. The amount of vaccinine in the shrub is, according to Mr. E. Claussen, about 1 per cent.; it forms long acicular crystals, of somewhat bitter taste and devoid of smell. This substance is scarcely soluble in ether, better so in cold water and alcohol, but best of all in boiling water; a saturated solution of this substance in the latter yields, on cooling, a solid mass. When the crystalline substance is heated, it melts to a clear liquid. It is not precipitated by either sub-acetate of lead or tannin, is neutral to test-paper, and contains no nitrogen.— American Journal of Pharmacy.

The Action of Alcohol on the Body.-Dr. Parkes and Dr. Wollowicz have published in the Proceedings of the Royal Society a very valuable paper, from which we take the following:-It appears, then, clear that any quantity over two ounces of absolute alcohol daily would certainly do harm to this man (the subject of the experiment); but whether this, or even a smaller quantity, might not be hurtful if it were continued day after day, the experiments do not show. It is quite obvious that alcohol is not necessary for him; that is, that every function was perfectly performed without alcohol, and that even one ounce in twenty-four hours produced a decided effect on his heart, which was not necessary for his health, and perhaps, if the effect continued, would eventually lead to alterations in circulation, and to degeneration of tissues. It is not difficult to say what would be excess for him; but it is not easy to decide what would be moderation; it is only certain that it would be something under two fluid ounces of absolute alcohol in twenty-four hours. It will be seen that the general result of our experiments is to confirm the opinions held by physicians as to what must be the indications of alcohol both in health and disease. The effects on appetite and on circulation are the practical points to seize; and if we are correct in our inferences, the commencement of narcotism marks the point when both appetite and circulation will begin to be damaged. As to the metamorphosis of nitrogenous tissues or to animal heat, it seems improbable that alcohol in quantities that can be properly used in diet has any effect; it appears unlikely (in the face of the chemical results) that it can enable the body to perform more work on less food, though by quickening a failing heart it may enable work to be done which otherwise could not be so. It may then act like the spur in the side of a horse, eliciting force, though not supplying it.

The Poisonous Efects of the Icaja of Gaboon.-The Comptes-rendus of August 8 contains a very valuable paper on this subject, by MM. Kabuteau and Peyre. It seems that at the Gaboon there is in use a vegetable poison,

locally known as m'boundou, or icaja. That substance is the root of a plant, which is not further specified. The authors have been experimenting with this substance, which, even in very dilute decoctions, is very bitter, and appears to contain one or more alkaloids, since the aqueous decoction is largely precipitated by iodide of potassium, and also by phospho-molybdic acid. The poisonous effects of this substance bear some similarity to the effects of brucia, but the authors state that, under certain conditions, this poison does not hurt men. Some of the lower animals are readily killed by it; a dose of 3 milligrms. of the alcoholic extract, placed under the skin of a frog, kills it; and rabbits and dogs are killed by doses of from 15 to 25 centigrms. of the same extract introduced into the stomach.

Relation between White Blood Corpuscles and Pus-cells.-Very few of the many questions which have turned up of late years have received so much consideration as this one; yet it is still unsettled. If we may judge from a paper published by M. Picot in the Comptes-rendus, June 20, it would seem that the idea of Conheim, that the pus-corpuscles are partly produced by the passage of the white blood cells through the blood vessels, is altogether a mistake-is a misinterpretation of the phenomena in point. M. Picot, whose memoir was presented by M. Robin, gave a tolerably long account of his observations on the circulation of frogs and mammals, and he declares most positively that the white blood cells never pass through the vascular walls, and that the pus-cells are formed gradually, external to the capillaries. He explains the error of Conheim and others by stating that they confounded several focal planes together, and he considers that he has demonstrated this in the following way. He counted the number of white blood cells in the arrested blood in the capillaries, both before and after the quasi-exuded corpuscles appeared. In both instances, he says, the numbers were the same, and this could not have been if the white cells had passed outwards. We must, however, express our doubts as to the method by which M. Picot was so well able to count the corpuscles on both sides.

Relation of Pigment Cells to Capillaries.-The Lancet has called attention to some valuable researches of Dr. Saviotti, which we should be sorry to omit noticing. The observer was engaged in studying the inflammatory process in the foot of the frog, and he first obtained a circumscribed spot of inflammation by means of a drop of collodion, and after a few days found the pigment cells of the irritated spot accumulated around the vessels in a contracted condition, and in the course of a short time that they had entirely disappeared. He immediately applied himself to the question of explaining the mode of their disappearance. In other frogs he excited inflammation by dropping on the web a small quantity of a 2 per cent. solution of sulphuric acid. Again, after a few days, he saw that the pigment cells had accumulated around the blood-vessels, and that, though they still preserved their contractility, their processes were less branched and numerous than natural. On further examination, he now observed that these processes began to penetrate the walls of the adjacent capillaries and small veins, causing an obstruction to the onward movement of the red corpuscles on their proximal side, while a clear space was observable on their distal side, occupied only by serum. And now one of two things occurred: either the process of the cell broke off, and was swept away by the blood current, or