dilute and render harmless noxious gases, to such an extent, that the working places of the pit's levels and workings, and the travelling roads to and from the working places, shall be in a fit state for working and passing therein, but that no owner, agent, or other person shall be held to have contravened this regulation, unless it shall be shown that all reasonable precautions have not been taken." This saving clause has been altered in the present Bill to:-" Provided that no owner, agent, or other person shall be held to have acted in contravention of this regulation, if it is shown that all reasonable precautions have been taken by the owner, agent, or person who is so charged."

This proposition is regarded as the turning-point of Mr. Bruce's Bill, and already loud is the cry amongst colliery owners and agents against it. "It cannot be supposed for a moment," says the 'Colliery Guardian,' "that they (the coal-owners) can take any other course than that of opposing it to the utmost, nor will they find any difficulty in showing that English legislation contains no precedent for an enactment which assumes that every person charged is guilty, and may be punished as such, unless he can prove himself innocent."

The question of responsibility is the one over which the battle will be fought. Every one is, of course, desirous of relieving himself from this burthen; and it is, indeed, a heavy one in some of our collieries, where the lives of hundreds of men are dependent entirely on the unceasing attention of a single mind. If the colliery owners and agents can relieve themselves of this by any pressure which they can bring upon our legislators, they will most certainly exert themselves to the utmost to secure the necessary force. We cannot ourselves see any alternative. The responsibility of securing the most perfect appliances, in every division of the workings of a colliery, must rest somewhere, and it cannot be allowed to be сараble of being shifted from one individual to another. In every colliery some head-man must be made responsible, and the Bill does not appear unjust on this point, for if this responsible head can show, after an accident has occurred, that every proper precaution had been taken, he will be held to be guiltless of any blame.

The employment of women and children, the payment of wages, the special rules and provisions as to arbitration, are all carefully dealt with in this Bill. The clauses which relate to inspection do not appear to us to be entirely satisfactory. Much has been said of the inability of twelve inspectors to visit, within the year, the 3000 collieries in the United Kingdom. It does not appear to us to be desirable that they should do so, but an earnest and intelligent man may make himself perfectly familiar with his district, without subjecting himself to the labour, or the coal-owner to the annoyance, of prying into the details of the subterranean workings. Lord Elcho remarked,-"The name of 'Inspector' was a misnomer, for the in

spectors did not profess to go into the mines, they merely held an inquiry when an accident had occurred. Accordingly they might with more truth be called 'Accident Inquirers." We fear a good and sufficient reply cannot be given on this point to Lord Elcho. Mr. Bruce, anticipating, as he could well do, from the discussions of last year, on the same subject, attempted to answer this, but all that he said, cannot be regarded as other than ingenious special pleading.

Mr. Lancaster referred to many of the causes leading to our present imperfect system of working for coal. To these we can only direct attention. His concluding remarks are of too much value not to be quoted:-" While many of the managers of mines were men of first-class education, and also of great practical experience, it was necessary that the younger men should receive a technical as well as a practical training. He hoped that as to some of these questions, the Home Secretary would adopt a much bolder course than that which he had yet taken, and would not hesitate to carry out the full recommendations which had been made."

Lord Kinnaird's Bill provides for the establishment of General Rules and Special Rules for Metalliferous Mines as nearly similar as possible to those proposed for collieries. It is evident from this that the different conditions of the two systems of mining cannot be correctly understood by his Lordship. The Bill provides for the effective ventilation of the metal mines, the depositing of plans with the Secretary of State (there never has been any objection to furnishing plans, as the large collection already in the hands of the Government in the Mining Record Office proves), and for such arrangements as are thought to be conducive to the health of the miners.

"Our Future Coal Supply" has claimed the attention of the South Staffordshire and East Worcestershire Institute of Mining Engineers, Mr. Richard Latham and Mr. George Spruce contributing two papers containing much important matter relative to the future workings of the thick coal of Staffordshire, and the probable extension of the Staffordshire field towards the coal-field of Shropshire.

Mr. Walter Ness, of Pelsall, also read a paper "On part of the Coal-field of Fife, N.B.," in which he proved, probably beyond much doubt, a large extension of this coal-field beyond the present workings. From this he adventures farther from the shore, and says:"If we take the total area of the Forth, where we have reason to believe those Coal-measures exist in their entirety, we have about 180 square miles in their entirety. . . and we get 12,672,000,000 tons. Taking the other parts of the nation (sea-bed ?) in like manner available, opposite Northumberland, Durham, and Yorkshire, and under the German Ocean, also opposite Ayrshire, Cumberland, Lan

cashire, and the Bristol Channel, on the west coast, as jointly capable of yielding a similar quantity of coal to that of the Firth of Forth, we shall then have 25,344,000,000." These are large figures-of their value we can only judge by the exactness of other statements made in this paper. "The investigation of the Royal Commission happily assures us that there is coal enough in store for several generations to come." Such is the opening paragraph of Mr. Walter Ness's paper. The fact being that the Royal Commission has not given one word of assurance in any form-and, we can state upon authority, that they are not yet in a position to do so.

METALLURGY.

There does not appear to be any novelty worthy of notice. The arrangements made upon the termination of one of the Bessemer Patents have led to considerable activity in the manufacture of Bessemer steel, and probably the result will be that, ere long, steel rails will almost entirely have superseded the iron ones, to which we have been so long accustomed.

A few interesting experiments are in progress, but none of the results yet obtained are sufficiently reliable to warrant our placing them on record.

11. PHYSICS.

LIGHT. It is a well-known fact that M. Schroetter proved that the action of sunlight converts ordinary phosphorus into red amorphous phosphorus. Sulphur, according to M. Lallemand, is similarly affected by the direct action of sunlight, inasmuch as the sulphur previously soluble in sulphide of carbon, and crystallizable, is converted into an amorphous modification insoluble in sulphide of carbon. The author placed a concentrated solution of sulphur in sulphide of carbon in a sealed tube, and exposed that tube some time to the action of the sun's rays, concentrated by a lens; this causes a copious precipitation of sulphur as an amorphous insoluble

matter.

Mr. Burt has examined the action of coloured light upon the Mimosa pudica. The plants are placed under glass jars constructed of variously-coloured glass. The chief fact observed in respect of these very sensitive plants is that by being covered with a greencoloured glass jar, the plant rapidly becomes insensible, and dies in a very short time.

The Rev. Father Secchi, after referring briefly to his former observations of the spectrum exhibited by Uranus, states that the

spectrum of Neptune consists chiefly of three lines, or bands, placed near the green, and that its light is entirely devoid of red; this is confirmed by the colour exhibited by the planet when seen through a telescope, which is a sea-green.

M. Feil has exhibited before the French Academy samples of perfectly homogeneous heavy flint-glass for optical purposes free from any bubbles or defects, and in masses weighing from 25 to 35 kilos. The process whereby this is obtained is not explained; but the statement is made that the crucibles having been protected from the effects of the lead, a heavier glass even than Faraday's can be made. The maker sent also a set of samples of beautifullymade artificial precious stones, not mere specks, but of good size. The aluminates of lime, of baryta and lime, of lead and of bismuth, are proposed for flint-glass; and the aluminates of magnesia and the silicates of magnesia and alumina for crown-glass.

M. Bontemps, the managing director of the celebrated glass works at Choisy-le-Roi, has arrived at the following results in connection with the coloration of glass under the influence of direct sunlight :-Within three months after having been exposed to sunlight, the best and whitest glass made at St. Gobain is turned very distinctly yellow; extra white glass (of a peculiar mode of manufacture) has become even more yellow, and gradually assumes a colour known as pelure d'oignon; glass containing 5 per cent. of litharge was also affected, but far less perceptibly; crystal glass, made with carbonate of potassa (the other varieties referred to contain carbonate of soda), litharge and silica, was not at all affected; English plate-glass, made by the British Plate-Glass Company, and exhibiting a distinctly azure-blue tinge, remained also unaffected. The author attributes the coloration, which begins with yellow and gradually turns to violet, passing through red pelure d'oignon, to the oxidizing effects of the sun's rays upon the protoxides of iron and manganese contained in glass.

M. Schinz states that platinum brought to bright white heat by means of the ignition of a mixture of hydrogen and carbonic oxide gases, yields a light which, in relation to good coal-gas, is as 1.24 to 1.0.

Professor B. Silliman has examined, in a lengthy series of experiments, the relation between the intensity of light produced from the combustion of illuminating gas and the volume of gas consumed. His experiments prove, among other matters, this theorem-that the intensity of gas-flames (i. e. illuminating power) increases, within the ordinary limits of consumption, as the square of the volume of the gas consumed. The chief point of interest, for the consumer of gas, to be deduced from the data here presented is, that where it is important to obtain a maximum of economical effect

from the consumption of a given volume of illuminating gas, this result is best obtained by the use of burners of ample flow.

HEAT. According to MM. Troost and Hautefeuille, carbon when combining with oxygen, only gives out 8000 caloric units; boron, under the same conditions, yields 14,400 caloric units; while, when boron combines with three equivalents of chlorine, 104,000 caloric units represent the heat set free.

The heat disengaged by the combination of 1 grm. of amorphous silicium with oxygen is 7830 units, with chlorine 5030. When 1 grm. of chloride of silicium reacts upon 140 times its weight of water, it is 2915; the heat disengaged when 1 grm. of amorphous silicium is converted into crystallized silicium is 290 units of heat.

Dr. St. Claire-Deville states that the oxygen dissolved during the fusion of platinum causes this metal to present the same phenomenon as molten silver-viz. scintillation and spirting while in the molten state.

In a paper "On the Heat given off by the Moon's Rays," M. Zantedeschi states that, as far back as the years 1685 and 1781, the Italian savants Geminiano, Montanari and Paolo Frisi proved the existence of rays of heat emitted by the moon, by means of lenses and ordinary thermometers. The author refers to his observations made some twenty years ago, when he applied thermoelectric apparatus, as well as spirit thermometers and lenses, and obtained results fully confirming those made and recorded by the Italian savants just alluded to.

In Germany the doors of the steam-boiler furnaces are now very generally provided with square pieces of mica, properly fastened, by means of which the fireman is enabled to observe the fires without the necessity of opening the furnace-doors too frequently, which is injurious, on account of interfering with the draught and proper course of combustion of the fuel, by reason of the access of irregular currents of cold air. Mica withstands a very high temperature; and the accidental breakage of the squares of this substance is guarded against by a properly-constructed iron-wire guard outside.

Dr. Ziurek states that gas from the brown coal from Furstenwald, five miles from Berlin, will shortly be made on the spot, and collected in Berlin in twelve gas-holders, each of a capacity of 750,000 cubic feet. The gas will be carried, as usual, in underground mains, and chiefly applied for heating purposes. 3000 cubic feet of this gas have a heating power of one-third of a ton of best coals, and are equal to 1 ton of best Prussian brown coal. 1000 cubic feet of this gas will cost about 5d. in Berlin; and the equivalent value of the heating power of this gas as compared with a