refers. The denticulations, which are intrinsic parts of the bone bearing them, are of two sizes-the smaller ones about half a line in length, the larger ones from two to three lines. The latter are separated by intervals ́of abɔut half an inch, each of which is occupied by several of the smaller denticles. All the denticles are of a triangular or compressed conical form, the larger ones resembling laniaries. Sections of the denticles show under the microscope the unmistakable characters of avian bone. The length of the skull behind the fronto-nasal suture is two inches five lines; and from the proportions of the fragment of the upper mandible preserved, the author concluded that the total length of the perfect skull could not be less than between five and six inches. The author proceeded to compare the fossil, which he declared to present strictly avian characters, with those groups of birds in which the beak is longer than the true cranium-a character which occurs as a rule in the Aves aquaticæ.

The

The Phylogeny of the Mammalian Orders.-This has been attempted to be formed by various palæontologists, with several degrees of success. latest is that by an American geologist, Professor E. D. Cope, in a paper which was read before the American Philosophical Society on April 18, and published May 6, 1873. The paper is too long for abstract here; but we may give the tabular plan, of which the author says:— "The accompanying diagram is designed to express to the eye more clearly the propositions made above. By comparing it with a similar table published by Prof. Gill ('Proceedings of the American Association for the Advancement of Science' for 1871, p. 295), a close resemblance between the two may be observed, as well as certain differences." He wishes to be understood that the genera named in it as ancestors are to be regarded in the light of types of groups. There is no other mode of explaining the facts, than that in accordance with the law of "homologous groups," i.e. that several genera of one group have undergone similar modification into corresponding ones of a second group.*

The Volcanoes of Hawaii.—In a late number of "Silliman's Journal," the Rev. T. Salt gives a graphic account of them. He says: "You have seen an account of the eruption within the great summit-crater of Mauna Loa in August, 1872. This continued for two or three weeks. On the 27th of January

* See "Origin of Genera," p. 79, Prop. V.

ever seen.

of the present year we had the grandest display from the crater that I have The action within it was vehement, and the scene marvellously brilliant. The great mural pit was in awful ebullition, and so violent was the raging of the molten sea within, that herdsmen of Reed and Richardson's ranch, on the eastern slope, reported the mountain as constantly quivering like a boiling pot. At Kapapala in Kau, at the base of the mountain, both foreigners and natives assert that they distinctly heard the swash of the fiery liquid, like the roaring and surging of a rushing river. The sheen of light, which rose thousands of feet heavenward and spread like a burning firmament over the mountain, was truly magnificent. At times the splendour was so vivid and so extended that observers called out the whole neighbourhood to witness the scene; some thought they saw the fiery river rushing down the side of the mountain; and numbers were sure that it was half way down the side, and that it was coming towards Hilo in hot haste. This, however, proved an optical delusion. The molten sea was confined within the deep crater, but it was fearfully grand. Parties were planning a visit to the scene of action, when suddenly the great furnace ceased blast. This was a little tantalising, but as we had all been favoured with free tickets to a royal display of fireworks, we could not mourn."

A Salt Deposit of Western Ontario.-Mr. J. Gibson, B.A., gives an account of this. The following is the depth of one of the wells:

1. Gravel, sand, and clay

2. Stratified dark-gray limestone

3. Stratified magnesian limestone, followed by a very hard layer of chert

4. Crystalline siliceous limestone, containing magnesia 5. Blue clay, shale, and limestone

6. Gypsum, shale, and salt

Feet.

25

€ 400

200

. 110

. 250

The drilling done in this well was unprecedented in the annals of this system of mining, both for speed and absence of mishaps. Actual boring commenced on the 10th of March, 1870, and the salt-bearing stratum was reached on the eve of the 22nd of the same month. After passing through 100 feet of pure rock salt, without the least evidence of change, the boring was abandoned. The great success attending this boring led to the sinking of two other wells, viz. :-Sparling and Merchant's, in the immediate vicinity; both, however, giving records similar to the above. Truly in no other portion of the American continent has there been discovered a deposit. of salt so magnificently great. The supply is practically illimitable, and may favourably compare with the production of the salt-mines of Droitwich, in Central England, or with that of the solid salt-hills of Cordova.

Rock Fissures and their Causes.-In a paper in the "Geological Magazine," Mr. T. Clifton Ward, F.G.S., after giving a long account of the subject, says, "How are such fissures to be accounted for? Does any one of the following suppositions seem likely ?—1. That they are strictly of the nature of slips; that is, the mass of the mountain, or any part of its mass,

is pressing outwards or towards the flanks. 2. That they have been caused by earthquake-shocks, perhaps very long since. 3. That they are the outward expressions of faults slowly taking place, and represent much greater disturbances or shifts at considerable depths. I can conceive," he says, "of no other theories than these to account for their formation. Let us consider their respective merits. With regard to (1) the facts that the mountain-side has no slipped appearance, and that the fissures often occur on a more or less flat-topped mountain, are against this supposition, though the ease with which one can imagine a great slip inclines one rather naturally towards it. That (2) is a possible cause no one will deny, though in this case it seems almost strange that the fissures should not be more frequent than they are, seeing that the shocks must always have been more or less felt over so small a district whenever they occurred strongly at one part. Against (3) an objection might be raised that they occurred only among certain rocks of the district, whereas faults would be likely to be found without any such marked restriction. But I do not think such an objection would hold; the non-occurrence of the fissures of this class among the Skiddaw Slate mountains is probably due to the nature of the rock; if fissured gradually, or even suddenly, the readily splintering and shivering slate would close the crack almost directly, so that it would be unperceived, whereas among the hard and blocky rocks of the Volcanic Series the fissure would stand open, or have large angular blocks wedged

in it."

The Structure of Crinoids.-Mr. J. Rofe, F.G.S., has published a capital paper on this subject. He says that through the kindness of Mr. E. Hollier he has procured pieces of columns from the Silurian formation at Dudley, including Taxocrinus, Periechocrinus, Actinocrinus, Marsupiocrinus, Cyathocrinus, and two columns undermined, as they were without heads. Of these he has had slices mounted for the microscope, and finds on examination that, although there appears to be a general similarity in construction with the round columns of the Mountain Limestone, as they are more metamorphosed by crystallisation, the details are more difficult to distinguish. Some of them exhibit pentaphylloid sections of the central canal, as the Taxocrinus and Cyathocrinus, whilst the Marsupiocrinus shows a rosaceous section, the petals being wide and the divisions between them forming very acute angles; but he cannot satisfactorily make out the fibro-cartilaginous structure round the canal, though, from appearances, it is probable that it would be found by further examination with a great number of specimens. This paper, which is of some length, will repay perusal.-"Geological Magagazine," June.

MECHANICS.

Improvements in Lamps for Diving Operations.-It appears that M. Pasteur has discovered that the vitiated air discharged by divers contains oxygen enough to support the flame of a petroleum lamp. He accordingly connects, with the flexible escape-pipe of a diver's helmet, a suitable lamp of the above description. The lamp may be carried in the hand of the diver

'or attached to any part of his person. The flow of the escaping air from the helmet through the lamp gives a bright flame, enabling the diver to see in all directions, rendering the employment of the expensive electric light no longer necessary.

A Pneumatic Sewing-machine.-An apparatus of this description has been lately patented by Mr. J. E. Holmes. It consists of a sewing-machine having, below the table, a train of gear-wheels and an air-pump, operated by a crank, the pump being used to exhaust the air from a cylinder, underneath a piston which traverses the cylinder. The exhaustion of the air causes the piston to descend and drive the sewing-machine. If a vacuum equal to 14 lbs. to the inch can be obtained, the piston being nine inches in diameter, the pneumatic pressure on the piston will be 890 lbs., equal to a weight of that amount falling say three feet, the height of the sewingmachine table under which the piston is placed.

Improved Railway-carriage Brakes.-These have been described to the Society of Engineers by Mr. W. H. Fox, C.E. His conclusions are that every engine and carriage should be fitted with brake apparatus capable of reducing it from a speed of sixty miles per hour to a state of rest in a distance not exceeding 220 yards on a level, in ordinary weather; that a retarding force of 18 per cent. of the weight of the train is sufficient to do this; that cast iron is generally more suitable than wood as a material for brake-blocks; and that experiment shows that a pressure of 23 tons is required to be applied to the cast-iron blocks fitted to each of the four wheels of a carriage weighing 10 tons, and 1·8 ton if wooden blocks be used in like manner. The author considers that the atmospheric brake complies with nearly all the conditions necessary to be fulfilled by a perfect continuous brake. See also "Scientific American."

An Instrument for bringing up Portions of the Ocean-bed has been discovered by a blacksmith on board the ship Hydra. The Challenger, the exploring ship now on a voyage of discovery round the world, is supplied with a number of these instruments. The machine consists of a hollow metal rod, fitted with valves, and on which are rove cast-iron weights of 100 lbs. each, one for every 1,000 fathoms of estimated depth. The whole is so adjusted that the weights detach themselves on striking the bottom, and only the rod, with the soil within it, is recovered. When the Challenger started on her voyage, some months ago, she had thirty of these weights, which will probably have to be replenished before she has completed her work. A much better instrument (in the opinion of the "Scientific American ") for deep-sea sounding is that invented by Sidney E. and G. L. Morse, brother and nephew of the late Prof. S. F. B. Morse, patented in New York in 1866. This machine consists of a rod containing a series of hollow glass balls, by means whereof (the number of balls being increased or diminished) any desired degree of buoyancy may be imparted to the instrument. Bags of sand or stones are attached, by which the rod is carried down, and the lower end made to scoop up a portion of the ocean bottom. The sand-bags become detached when the rod strikes bottom, and the rod then rises with amazing velocity to the surface, shooting up into the air as if discharged from a gun. This instrument is also provided with glass-pressure chambers and mercury, so arranged that the pressure

of the water will drive the mercury from one chamber to the other. The depth of the ocean bottom will be indicated by the quantity of mercury so exchanged. The register of depth is very exact. This sounding instrument requires no line, and is, we believe, the first of the kind ever invented.

How to Ascertain the Strength of Metals.-Various plans for this purpose have been used from time to time. That of Prof. Thurston is thus described: “Work has now been commenced upon the metals, and the Professor desires to obtain samples of all well-known brands; the specimens to be 3 inches long, and of 1 inch round bar or and square bar, with, in each case, statements as concise as possible of the ores used and method of manufacture of the sample, with the understanding that the results may be published. The specimens may be sent to the Institute at any time. The work was interrupted May 24, and during the absence of Prof. Thurston to attend to his duties as a member of the United States Scientific Commission to Vienna, but have been resumed on his return in September. We noticed a specimen of Ulster iron taken from open market, which had twisted to the limit of the machine, over 200°, without breaking off. The specimens are turned down in the middle, the neck being 1 inch long and inch in diameter, by Whitworth gauges."

MEDICAL SCIENCE.

Spontaneous Coagulation of Milk is Caused by Microzymas.-According to a paper by M. A. Béchamp in a late number of the " Journal de Pharmacie," the main cause of the spontaneous coagulation of milk is the presence therein of minute living organisms, which may be detected in the milk by first diluting it with from five to six times its bulk of creosote water (neither the degree of concentration nor the mode of preparation of this fluid are quoted), and next filtering the milk, care being taken to protect the filter from dust. The filter is first washed with ether, for the purpose of eliminating the butter; next, with a dilute solution of carbonate of soda, for the purpose of dissolving some caseine; and lastly with distilled water. On inspection with the microscope (magnifying power 500 diameters) the microzymas will be seen.

Is there such a thing as Muscular Sensation?—The results of M. Bernhardt's experiments to determine whether the so-called "muscular sense" comes from the muscles or from some other source are not without some interest. The author does not deny a “sense of force," but claims that it may be only a consciousness of the degree of excitement in the nervous centre which acts on the muscle, or that it may be owing in part to sensations in the soft parts adjacent to the muscle. Bernhardt passes in review the various arguments pro and con. Spiess and Schiff pronounce decidedly against sensation in the muscles. Mechanical and chemical excitements of the muscles produce neither pain nor reflex movements, as has been shown by Pikford and Arnold. Cramps, indeed, cause pain; but this may result from compression of nervous filaments traversing the muscles. It is doubtful, moreover, whether the muscles receive sensory nerves; for it has been