I mixed together sulphuretted hydrogen in a high degree of purity and oxymuriatic acid gas both dried in equal volumes in this instance, the condensation was not; sulphur, which seemed to contain a little oxymuriatic acid, was formed on the sides of the vessel; no vapour was deposited; and the residual gas contained about of muriatic acid gas, and the remainder was inflammable.

MM. Gay Lussac and Thenard have proved by a copious collection of instances, that in the usual cases where oxygen is procured from oxymuriatic acid, water is always present, and muriatic acid gas is formed; now, as it is shewn that oxymuriatic acid gas is converted into muriatic acid gas, by combining with hydrogen, it is scarcely possible to avoid the conclusion, that the oxygen is derived from the decomposition of water, and, consequently, that the idea of the existence of water in muriatic acid gas, is hypothetical, depending upon an assumption which has not yet been proved-the existence of oxygen in oxymuriatic acid gas.

MM. Gay Lussac and Thenard indeed have stated an experiment, which they consider as proving that muriatic acid gas contains one quarter of its weight of combined water. They passed this gas over litharge, and obtained so much water; but it is obvious that in this case they formed the same compound as that produced by the action of oxymuriatic acid on lead; and in this process the muriatic acid must lose its hydrogen, and the lead its oxygen; which of course would form water; these able chemists, indeed, from the conclusion of their memoir, seem aware, that such an explanation may be given, for they say that the oxymuriatic acid may be considered as a simple body.

I have

I have repeated those experiments which led me first to suspect the existence of combined water in muriatic acid, with considerable care; I find that, when mercury is made to act upon 1 in volume of muriatic acid gas, by Voltaic electricity, all the acid disappears, calomel is formed, and about .5 of hydrogen evolved.

With potassium, in experiments inade over very dry mercury, the quantity of hydrogen is always from 9 to 11, the volume of the muriatic acid gas used being

20.

And in some experiments made very carefully by my brother Mr. John Davy, on the decomposition of muriatic acid gas, by heated tin and zinc, hydrogen equal to about half its volume was disengaged, and metallic muriates, the same as those produced by the combustion of tin and zinc in oxymuriatic gas, resulted.

It is evident from this series of observations, that Scheele's view, (though obscured by terms derived from a vague and unfounded general theory,) of the nature of the oxymuriatic and muriatic acids, may be considered as an expression of facts; whilst the view adopted by the French school of chemistry, and which, till it is minutely examined, appears so beautiful and satisfactory, rests, in the present state of our knowledge, upon hypothetical grounds.

When oxymuriatic acid is acted upon by nearly an equal volume of hydrogen, a combination takes place between them, and muriatic acid gas results. When muriatic acid gas is acted on by mercury, or any other metal, the oxymuriatic acid is attracted from the hydrogen, by the stronger affinity of the metal; and an oxy muriate, exactly similar to that formed by combustion, is produced.

The

The action of water upon those compounds, which have been usually considered as muriates, or as dry muriates, but which are properly combinations of oxymuriatic acid with inflammable bases, may be easily explained, according to these views of the subject. When water is added in certain quantities to Libavius's liquor, a solid crystallised mass is obtained, from which oxyd of tin and muriate of ammonia can be procured by ammonia. In this case, oxygen may be conceived to be supplied to the tin, and hydrogen, to the oxymuriatic acid.

TO BE CONCLUDED IN OUR NEXT.

On the Coal Mines of Sarrebruck, and on the Management of Mines in general.

By M. A. H. DE BONNARD, Mine Surveyor.

From the ANNALES DE CHIMIE.

THE intention of this paper is to exhibit a view of the management of the coal mines in the neighbourhood of Sarrebruck. As it is intended to exhibit a specimen of the manner in which mines are managed in Germany, in order to instruct the government on that subject, and to propose the application of the principles upon which that management is founded, it is necessary to make a comparison between the management of mines in France and Germany. This comparison will, in fact, be only a succinct abridgement of a very large report which M, Heron de Villefosse, surveyor-general of the mines in France, and inspector-general of the mines and smelting-houses in the conquered countries, sent in the be

ginning

ginning of the year 1807 to the superintendant-general of the army, and to the board of mines at Paris. The farther developement may also be found in a report presented by the same author to the king of Westphalia, and which has been ordered to be printed by the mipister of the interior of the French empire. In the first place, some notice will be taken of the improvements that might be made in the general management of mines throughout France, in order to apply the same in a more detailed manner to the mode in which the govern, ment ought to dispose the mines at Sarrebruck, in order to gain as much as possible by them.

France is one of the richest countries in respect to mineral substances. Its actual absolute mineral richness, that is to say, the value of all the substances extracted from the bowels of the earth may be certainly calculated at more than one hundred millions of francs (4,166,6667.), and yet a considerable part of the richest mines in its territory is not worked; and the indications exhibited by many of the departments in respect to the minerals they contain have not been followed up. It is certain, that if the mines that have been abandoned were again worked, and those new mines which are the most promising were opened, these absolute riches would be greatly augmented. Although France always enjoyed a very considerable mining capital, it is nevertheless certain, 1°, that the old government drew but a very small profit from mines; 2, that the balance of trade, in respect to the produce of mines, was very much against France. In 1787 this disadvantageous balance was no less than 36,569,000 livres (1,523,708/.), laying aside -gold and silver; and it still remains, in a great measure, notwithstanding the important establishments that France

has

1

has acquired since that time, and which are comprehended within its present limits.

If the mineral riches of France are compared with those of several states celebrated for their mines, as Austria, Prussia, Saxony, Hanover, Hesse, &c. it will be seen that the absolute mineral riches of France is far more considerable than that of any of those countries; and its relative mineral richness, when considered in proportion to its extent or to its population, is either more considerable, or very nearly equal to that of the states which possess the richest mines. Nevertheless, if the revenue that each of these countries derive from their mines be examined, it will be found that a considerable revenue, arising from the mines, is annually paid into the treasuries of their sovereigns; and that the commercial balance of the substances extracted from mines is rendered advantageous to them in a considerable degree, while this is not the case in France.

Thus, to take Prussia as an example, in which, as in France, the principal mines are of coal or of iron, the absolute mineral richness in 1806 was only nine mil lions of francs (375,000l.), but its relative mineral richness considered, in respect to its extent, was only onefourth of that of France considered in the same point of view, and in respect to its population only one-third. Nevertheless, at this very period, the commercial balance of the products of mines was 2,152,168 francs (89,6737.) in favour of Prussia, and the sovereign drew from them a net annual revenue of about 600,000 francs, or 25,000l.

Similar results have been obtained in the other countries just mentioned. Is it not, therefore, to be supposed, that the striking difference between these results VOL. XVIII.-SECOND SERIES. Р

and