form mountain ranges.

The conglomerate consists of trap pebbles in trap sandstone; the trap is sometimes compact, at other times amygdaloidal. The strata run in a curvilinear direction. They dip to the north, with a slope of 16° to 30°, the veins are at right angles to the strata, and run nearly north and south. The veinstones are steatite, quartz, calcspar, and zeolites. The ores are those of copper, silver, iron, and lead, the two former being productive. The two metals are chiefly native, but occur also in other forms. They are least abundant in the conglomerate, more so in the trap, most of all in the amygdaloid. They are found also in amygdules of the rock near the veins. The quantity of native copper is very great. In the Copper Falls Mine, near Eagle Harbour, on sinking a pit to 72 feet, the compact trap and amygdaloid were found to alternate six or seven times. The main vein was 18 to 20 inches thick. In the shaft, about 40 feet down, a mass of native copper was found, of which the dimensions were estimated by the author, in situ, to indicate a weight of about 30 tons. It had not yet been found possible to remove it. A diagram of its position was given.

From other shafts in the vicinity, much copper had been extracted, but with prodigious difficulty, from the tough metal binding the rock firmly together, and rendering blasting useless. The author saw, on the surface, besides many pieces of 25 lb., seven masses, varying from 75 to 1200 lb., and weighing in all 4000 lb., or nearly 2 tons. Native silver is found with the copper, and a mass of 31 lb. had been obtained. The author saw one of 14 lb. The author is of opinion that the very richness of this mine in native copper may render it unproductive, from the difficulty and expense of working it.

In the Cliff Mine, on Eagle River, there is the same abundance of copper, with more silver. Part of the rock was said to yield 7 per cent. of silver; but subsequently was found hardly to pay for its extraction. The author saw here a mass of silver of 31⁄2 lb. vein in the trap seen by the author contained native copper. the Eagle River Mine, silver is found in large masses, one of which weighed 7 lb. 2 oz.

Every
At

On the Canada side, as far as the author had then examined it, from Fort-William to Pigeon River, indurated shale prevails, overlaid by greenstone, with patches of porphyry. Many trap-dikes are seen, forming long narrow promontories and deep harbours on the

shore of the lake. A system of veins occurs at right angles to the dikes, containing barytes, in addition to the veinstones formerly mentioned. The veins vary from 6 inches to 20 feet. In one of them 14 or 15 feet thick, well seen on Spar Island, gray sulphuret of copper occurs in considerable abundance, especially in a part of the vein, nearly 5 feet thick. Native silver also occurs in small quantity. There are also veins parallel to the dikes which contain ores of copper. But the author could not form a decided opinion in 1846

of the value of these mines.

In the second letter, he gives some of the results of an examination of the eastern townships of Canada, from Lake Champlain and the Richelieu to the Chaudiere. He observed facts proving the green mountains of Vermont to be more recent than the Loraine shales, or Hudson River group. Of the upper rocks, the most interesting was a band of serpentine, 150 to 400 yards broad, which the author traced continuously for 150 miles, and which probably extends as far again. It has occasionally rich beds of magnetic iron and of chromate of iron; of the latter, a boulder was found, weighing 6 cwt. The gravel on the Chaudiere, besides these minerals, contains titaniferous iron and gold. The author expects to find platinum, as the gravel in all other respects resembles that of the Russian auriferous district. The auriferous sand is found on the tributaries of the Chaudiere. It will probably pay for extraction. 60 bushels washed by Mr Derby, yielded 18 dwt. 8 gr., or about 1s. 6d. worth per bushel. The gold has not yet been found in situ.

3. Notes on Practical Chemical subjects. By Alexander Kemp, Esq. Communicated by Professor Gregory.

1. On the Purification of Sulphuric Acid.

The author, after describing the different methods, recommended for purifying sulphuric acid from nitric acid, namely, boiling with a little sugar, and heating with sulphate of ammonia, both of which had proved troublesome and imperfect, stated, that after trying various plans, the only one which he found to answer well, was the action of sulphurous acid on the oil of vitriol, after diluting it to the sp. gr. of 1.715, or lower. He adds one volume of water to three of the oil of vitriol, passes sulphurous acid gas through the hot liquid till it is in excess, and then boils off the excess of sulphurous acid; or, still better, three volumes of oil of vitriol are added to or diluted with, one of a saturated solution of sulphurous acid in pure water,

and boiled. The acid is thus so perfectly purified from nitric acid, that when used for making hydrochloric acid, it yields a product quite colourless, which was not the case with the oil of vitriol purified by any other process.

If the oil of vitriol be diluted with one-half its volume of sulphurous acid solution (or of water, previously to passing the gas through it), the sulphate of lead is also totally separated, and the clear liquid, decanted from the precipitate, and boiled down to sp. gr. 1.845, is colourless, and almost chemically pure.

2. On the Preparation of Pure Hydrochloric Acid.

Professor Gregory, in his process for preparing hydrochloric acid, by heating 1 equivalent of sea-salt with 2 equivalents of sulphuric acid of sp. gr. 1·650, directs the use of patent salt, to avoid the presence of iron in the product.

The author observed, that there is always a certain quantity of iron in the residue, even when patent salt is used; but that none passes over with the hydrochloric acid. He then added iron and peroxide of iron in considerable quantity to the materials. Still no iron passed over. It would appear, that when iron had been observed by Professor Gregory in minute quantity, in the hydrochloric acid made by his process, from common salt, it had either passed over at the very end of the process, when the temperature rose very high, although the author could not, in his own experiments, observe this, or, more probably, had been present in the test employed. It is probable that, even when much iron is present in the materials, the presence of the excess of sulphuric acid, and also the low temperature at which the process goes on, prevent the formation of the chloride of iron.

The author's observations enable us to prepare, from the commonest and cheapest salt, perfectly pure and colourless hydrochloric acid, and thus still further to reduce the price of this reagent, so essential to the chemist.

Professor Gregory also briefly stated some observations by Mr Kemp and himself, on the purification of chloroform, which he was to describe more fully at a subsequent meeting.

Dr STARK

Was balloted for, and duly and unanimously re-elected a Fellow of the Society.

Monday, 4th March 1850.

General Sir THOMAS MAKDOUGALL BRISBANE, Bart., President, in the Chair.

The following Communications were read :

1. Analysis of the Anthracite of the Calton Hill, Edinburgh. By Dr A. Voelcker. Communicated by Dr George Wilson.

that we

Dr Voelcker observed, in the introduction to his paper, are in possession of analyses of anthracite from different localities, from which it appears that different specimens vary much in the proportion, but very little in the nature, of their ingredients. All samples of anthracite which have been analysed, have been found to contain carbon, oxygen, hydrogen, and nitrogen, as well as more or less inorganic matter. Sulphur also has generally been found, at least when sought for; but it does not appear in many recorded

analyses.

The anthracite employed in the following analyses was furnished by Dr Fleming, and first carefully dried, after being finely powdered, by exposing it for several hours to a current of dry air, at a temperature of 230° F. The carbon and hydrogen were ascertained, by burning from three to four grains of the mineral with a mixture of oxide of copper and oxide of lead, which is much less hygroscopic than the pure oxide of copper. A mixture of this oxide and chlorate of potass was also placed in the shut end of the combustion-tube, from which oxygen was evolved in the usual way towards the close of the process.

The nitrogen was determined by Will and Varentrapp's method. The sulphur was ascertained by projecting into a red-hot platina crucible, in successive small quantities, a mixture of anthracite in powder, with nitrate of potass and carbonate of soda, and afterwards maintaining the product of deflagration at a high temperature for some time. The resulting fused mass which was perfectly white, was dissolved in water, super-saturated with hydrochloric acid, and precipitated by chloride of barium.

About ten grains of the mineral were employed in the determination of the amount of ash. It was red, and contained oxide of iron. The following are the results of the analysis:-

The most remarkable peculiarity of the Calton Hill anthracite, as appears from the results given above, is the large proportion of sulphur it contains, amounting to nearly 3 per cent. Sulphur has been supposed to occur in the different varieties of coal in combination with iron, as pyrites, but the trace of that metal present in the Calton Hill anthracite is so small, that the sulphur must have been combined with the organic constituents of the mineral.

Note on the Crystallisation of Carbon, and the possible derivation of the Diamond from Anthracite and Graphite. By Dr George Wilson.

The author stated that the object of his communication was, to suggest the possibility of anthracite as well as graphite being substances from which the diamond is developed. After referring to previous theories, as all assuming that carbon must have been fluid. or semifluid, before it crystallised, he stated that his hypothesis contemplated the possibility of graphite, as well as amorphous carbon, and its solid combinations, such as anthracite, undergoing crystallisation into the diamond, without losing their solidity during the change. He thought anthracite more likely than most substances to yield the diamond, for the following reasons:

Firstly, As it occurs in nature, in many localities, it is found passing by insensible gradations, on the one hand, into common coal, on the other, into graphite; so that it may be regarded as representing the transition-state from fossilised vegetable matter to pure carbon, and as tending, under the influence of certain agencies, to change ultimately into the latter.

Secondly, The chief element of anthracite is carbon, of which it frequently contains 91, and sometimes 95 per cent.

Thirdly, Its other ingredients (with the exception of the ash, which is often under one per cent.), namely, hydrogen, oxygen, nitrogen, and sulphur, form volatile compounds with each other, and with