An American Company has passed through Carthagena for Choco lately, whose object is to search for gold mines in Choco and Antioquia.

It is said a coal mine has been discovered on the Rio Leon at the mouth of the Atrato, in the gulf of Darien. Some scientific men started from Carthagena about the 20th July last, to test the truth of this matter.-the gentlemen are Americans.

A surveying party has also passed through Carthagena, for the head waters of the Atrato, to survey Blag's route from the river Quito to the San Pablo.

HOW THE GREAT GOLD NUGGET WAS FOUND.

The following narrative is given in the Manchester (England) Guardian as the version of one of the diggers who found the monster nugget of 134 lbs. 11 oz. at Ballarat. The account runs thus:

My cousin John Evans, and myself, left England for Melbourne on the 2d of June, 1852, by the Lady Head. We have both worked in coal mines, I was a sinker; and we thought if gold was to be had, we could get it. We had a good passage out, arriving in 83 days. We found hundreds of people without shelter; many lay in the streets, and many in the watch-houses. We found out a fellow townsman, and he let us sleep on the floor of his kitchen. We didn't stay long there; just enough to see about. Things were very high then, but the diggers spent money like dirt. Almost the first man we met on shore was drunk, and swore he'd spend £500 before he left the spot. We saw the man who found the big nugget. He was drunk, too, on horseback, and shouted out "I'm the boy who sold the nugget for £4000." They told us he was always drunk since he found it.

We bought a blanket, tent, and some tools, chose a space (they allow you 16 feet square), and went to work. The first day we got an ounce apiece, after sinking two or three feet. This was in Sheepshead Gulley, in a clayey soil. Worked here six weeks, and got between 5 lb. and 6 lb. weight of gold, but the water began to fail us, and we suffered badly from dysentery. It's all surface

water. I only saw one spring in the country. Hearing of a rush to the "Ovens " we decided to go, and it was there we were joined by our mate (Lees) and two other men. We bought a horse and cart for £84, and three months' provisions. Flour cost us £15 a sack, or 1s. 6d. a pound; salt, 2s. 6d. a pound; butter, 5s. 6d. Tea and coffee were cheap. We had to buy fire-arms and guard the horse night and day. 'Twas a dreadful journey through the bush, and it took us more than a fortnight, being as we reckoned, 225 miles. When we got to Ovens, we found the diggings were 25 miles from the town. We didn't like the looks of the place; it was solid hilly ground; so we turned back and went straight to Melbourne, about 150 miles more. We sold our horse and cart here for £65; but we didn't stay long. We then concluded to try Ballarat, so we got a new rig out, and I and my cousin Lees, and a young man who came out by the Great Britain, named Green, made the party.

Green had been railway clerk in Wolverhampton ; but seeing there was no call for clerks out there, he would go with us. We went by the steamer to Geelong, and then, with our blankets and rifles on our shoulders, we walked through the bush to the diggings. We had hard work here to get food. We couldn't obtain any for love or money. We had no flour or damper, no salt; and for two days we lived only on what we shot, and very awkward it was to cook it too. Ballarat is about 60 miles from Geelong, and we fixed our tents there, outside the diggings. We always liked that plan best. We then had a good look all over, which took us some days. I was out one day, and I thought I would have a look at some of the old holes, and I went down many of them between 30 and 50 feet deep. I liked the looks of two of them, and we set in to work and got about 11 lbs. of gold in about a week. We marked where the dip in the strata was, and began driving a level tunnel. The first day we got

gold. We tried other holes after that. In one of them I went down I found a

pillar left for support, so we cut down some trees and made props, took the pillar away, and got more than a pound of gold out of it. Then we thought we would try two new holes, but we didn't like the looks of them we began to sink; so we deserted them, and tried the old ones again till the find began to fall short.

One morning I threw my gun on my shoulder, and started off for another ramble, and about three miles off came to a likely place called Canadian Gully. I liked the looks of this amazingly, and went back and reported. Next morning all went over with the tent, and marked out two spaces. We began two shafts, 37 inches in diameter. Cousin Jack and I dug and sunk; Green and Lees hauled and carried. We soon came to good soil, and worked away in earnest at our hole. We found gold very soon, and worked night and day; in a few days we got down 50 feet, and got 8 lb. or 9 lb. of gold. Then we had a good offer for the hole, and sold it, and set to work upon the other shaft. This was a troublesome one, for the water rose at 20 feet, but we got more timber, cut and cased the shaft, and then got rid of the water, and soon came upon the clay and gold.

About 66 feet deep we found the bottom of sandstone and slate, so we began driving a level again, and one day 'twas my turn down, and in the tunnel, about 30 inches high, and a yard wide, I found some very good nuggets, and when I came up I said to Jack, in a joke, "this is the way to get gold; you don't know how to get it." But he said "he should find some, some day;" and sure enough he had not been down long before I heard him laughing like mad and calling me. I leant over the shaft, and he could hardly speak. "What is it, Jack?" I said. "I've found it!" said he, "and it's a big'un." "Softly," I said, "for God's sake, keep quiet; how big is it?" "Three or four hundred weight," he said, laughing again; so I begged him not to make a noise, and I went and called Lees, and took him away from all the tents, and told him Jack had found a big nugget, and we must keep it dark. So I got an old sack, and sent it down the hole, and Jack soon sent up the gold; I slung it over my shoulder, and walked quiet-like through all the diggers till I came to our tent, and then I threw it down outside on the dirt heap, and went inside to consider what was best to be done.

Leaving Lees to watch, I went off to the agent's, two miles off, to ask for protection. "What for, Evans?" "We've found a large nugget, sir." "How big" he says, "forty pounds?" "Well, sir." I said. "I think it's twice forty.” Oh! you're romancing," he says; but he sends three police and a horseman, and just at sunset they slung the sack on a pole and carried it off to the government station. It was soon all over the diggings, and one man bid up £250 for the hole; but we wanted £300. Next morning we went to the commissioners to get the nugget washed and weighed, but it was licence day (every body has to take a licence at the diggings-visitors and all), and there was such a crowd of people that we left off washing it; and when they all went away we weighed it in an old pair of potato scales, and it weighed 134 lb. 8 oz. or 111 lb. avoirdupois. While we were at the agents, we told our mates, Green and Lees, to sell the hole, and some Lancashire folks offered £300 if they'd let 'em try it first.

So one of 'em, went down, and in the second basket of mud they sent up another nugget, which weighed 55 oz. 10 pennyweights, but they didn't know it was there; and when Lees told 'em they closed the bargain; and sent no more buckets up. The commissioners advised us to leave the place as soon as we could, there was a great excitement about it; and as we went through the diggings they told us our mates had found another big nugget, but we didn't believe 'em, there's always so many romances flying about there; but we found 'twas true this time. Getting a receipt for the gold, we set off for Melbourne, but found the news had gone before, and one gentleman offered us on the Geelong boat £5 an ounce for the big nugget, if 'twas half stone, but we wouldn't sell it. So waiting for the escort, we embarked with all the gold we had on board the Sarah Sands, and after a long passage landed at Plymouth (the ship

carried six tons in all, and at last saw it safely housed in the bullion office of the bank of England.

[By the last arrivals from Australia we learn the Ballarat nugget has been eclipsed by a more brilliant discovery, namely, the finding of two enormous masses of gold in quartz, weighing upwards of 186 lb. 11 oz. 10 dwt. troy.]

GARDNER'S MAGNETIC GOLD WASHER.

THE method by which this separator and amalgamator is used, is as follows:

In the first place, a suitable spot contiguous to the auriferous earth, or gold-bearing pulverized quartz, is selected. near to water, if possible; the machine properly put together, and if mercury is used, the furnace K, adjusted under the amalgamator J, and the smoke-pipe attached.

Accompanying each machine are three sieves, adapted to different kinds of earth; the cast-iron sieve is best for coarse or clay diggings, and the finer ones for sand or pulverized quartz rock. Adjust the sieve in the rocker B, kindle a fire in the furnace K, (if mercury is used,) put in a small amount of water, and pour the quicksilver into

the amalgamator J, and when the water is raised to about one hundred and fifty degrees temperature, or a little more than blood heat, the mercury and machine is ready for operation.

Shovel the earth into the rocker, and at the same time conduct in a stream of water if practicable; if not, pour in gradually with a bucket, turn the machine steadily, not too fast, and all the soluble earth, clay, and a large part of the white or gray sand will pass off with the water at the side of the machine, and the black sand or oxide of iron will be removed by the magnets and brushed off at the rear end, and the gold be detained in the bottom of the amalgamator.

The handling and use of quicksilver requires care, but when cold, it is perfectly harmless, and only becomes injurious when heated to such a degree as will cause the white mercurial vapor to rise from the surface; which, if inhaled, will produce injurious, and sometimes fatal results, and hence the necessity of a perfectly tight and well secured retorting apparatus.

In using the Retort, put in the amalgam, after all the liquid mercury has been pressed out through buckskin. See that the edge, or place where the cover rests is free from dust or sand, that the joint may be perfectly tight; screw down the cover, and let the lower end of the pipe dip into a bowl of cold water. Put in the pipe firmly, place the retort over a coal or wood fire, as represented in the cut, and heat it quite gradually until red hot (if heated too suddenly, the vapor will form faster than the pipe can carry it off), and the great pressure will loosen the pipe, resulting in loss of mercury. The cold water in the bowl will condense the

mercurial vapor, restoring it to its natural state-quicksilver; and in this way it may be distilled thousands of times, without material loss, or injury to the operator.

After the mercury is all expelled from the amalgam, remove the fire or the retort, allow it to cool, and if the quicksilver is all expelled, the gold will appear of a natural gold color, and is then ready for market or melting.

NEWTON'S GOLD WASHER.

This late English invention relates to a mode of subjecting pulverized ores to the combined action of water and quicksilver, for the purpose of amalgamating the metallic particles thereof with the quicksilver, and of driving off the earthy and other refuse matters.

Fig. 1 is a vertical section of the apparatus employed by the inventor for the purpose; and fig. 2 is a plan view, with the vertical water and feed-pipe and conical cap removed. A, is a circular vessel for containing mercury, and provided with a rising conical bottom. On the surface of this conical bottom numerous curved grooves c, c, are formed, through which the water and pulverized ore are passed into the quicksilver. These grooves are covered with a hollow cap D, screwed firmly down through its flange E, and having a hole F, in its top, to receive the feed-pipe G, which fits in tightly, and is high enough to contain a column of water sufficient to force its way, with the pulverized ore, through the said grooves and the quicksilver in the vessel A, and pass off through the discharge-spout H. The mercury vessel is provided with an outlet 1, for discharging the amalgam as often as may be necessary.

Fig. 1.

Fig. 2.

The operation of the apparatus is as follows:The pulverized ore is placed on a sieve at the top of the feed-pipe G, and a constant stream of water is applied thereto; whereby the fine gold or other metallic matter is washed through the meshes of the sieve, and down the pipe into the diffusing grooves c, c; the pipe being meanwhile filled to a height sufficient to countervail the resistance of the heavy body of quicksilver, and force the metallic matter through the grooves at the bottom of the vessel A. into the mass of quicksilver. By this means the metallic particles become thoroughly mixed with the quicksilver, and the water and other light matter, rising up to the edge of the mercury vessel, pass off through the dischargespout H; while the gold or other metal is taken up by, and amalgamated with the quicksilver. This amalgam is drawn off as often as it may be necessary, by removing the plug from the outlet-pipe 1; and a fresh supply of mercury is then placed in the vessel A, ready for the next operation.

BUFFUM'S AMALGAMATOR.

I

Improved Gold-Washer and Amalgamator. Patented May 31st, 1853. ARNOLD BUFFUM, New-York City.

The figure annexed represents the gold-washer; 1 2 3 4 are centrifugal amalgamating compartments; 5 is a centripetal discharging compartment; 6 7 8 9 are agitators. The discharging aperture is in the centre of the bottom

of the centripetal compartment at 12, surrounded by a conical inclined plane. A series of circular channels, within one another, surround the conical inclined plane, and connecting with each other by openings; they are about two inches high; above is a revolving guiding table 10, which brings the ore in close contact with the quicksilver.

The bottom of the amalgamator is covered with quicksilver; the water and ore are introduced at 1, when it is agitated by the revolving wheel or agitator 6, which washes the ore and moves it through the connecting opening direct upon the surface of the quicksilver; when it has passed through 2 3 4, and it arrives at the compartment 5, the centripetal force carries the impurities

circularly in the channels through the aperture 12, when the inclined plane prevents the escape of the quicksilver.

"1st, I claim the furnishing of the centripetal discharging compartment, with a horizontally revolving, water-moving, and ore-guiding table, in combination with a discharging aperture, surrounded by a conical inclined plane at

the centre.

"2d, I claim the arrangement of the circular guiding channels, with connecting openings, so adjusted as to secure an irregular spiral passage from the periphery to the aperture at the centre.. I claim these arrangements for gold separators, whether the centrifugal and centripetal compartments be used in combination, or either of them separately."

BERDAN'S CRUSHER AND AMALGAMATOR.

WE are indebted to our friends of that valuable publication "The American Polytechnic," for the opportunity of laying before our readers the preceding and following illustration of recently patented Quartz Crushers and Amalgamators. Improvement in Machines for Pulverizing Auriferous Quartz and Amalgamating the Gold. Patented May 24th, 1853. HIRAM BERDAN, of NewYork city.

The nature of this invention consists in attaching, by a pin or axle, a box and sieve, as seen in the figure at S, a ball or sphere, X, of three thousand or more pounds weight, to the inclined shaft B of an inclined vase or bowl A, whose axis inclines a few degrees from a perpendicular, which ball or sphere is so fastened to the axis of the bowl as to have a combined rotary or spiral motion, by the turning of the said bowl upon its inclined axis, which may be effected by horse or any convenient power applied to gearing, which makes into the cogs on the periphery of the bowl at Y. This basin A is furnished with a proper supply of quicksilver, serving also as an amalgamator; the finely-pulverized gold is returned, while the earthy matters pass off with the stream of water flowing into the bowl