AMERICAN INSTITUTE. 453 



SOLDERING ALUMINUM, 



So difficult at first, is now done by M. Mowrej, of Paris. He prepares 

 tlie edges with a mixture of turpentine, balsam copaiva and lemon juice; a 

 jet of flame is blown along the part to be soldered ; the joint is then covered 

 with morsels of an alloy of 6 parts aluminum and 94 zinc. These he'mcr 

 melted, adhere to the surface, and are pressed down by means of small tools 

 made of aluminum, (or, as he calls it, aluminium). 



THE NATIONAL FLAX COMPANY, 



Use Cator'fe machine. After being lifted out of water, the flax is passed 

 in a continuous course through pressing rollers, and round cylinders heated 

 by steam into fluted rollers, whence it is conveyed by hand all ready dried 

 and broken to be scutched. The operation between the water and the 

 scutching, is done in less than fifteen minutes. One machine, in 10 hours, 

 makes half a ton of fibre and a quarter ton of tow. The sewing is from $25 

 to $50 per ton. 



The accompanying paper was read by Mr. Bruce on the subject of Gold 

 production : 



I have had no personal experience in any of the modes usually resorted 

 to for extracting gold from the rocks. My knowledge is obtained from my 

 sons in California, who have devoted some portion of their time to that 

 object, 



I have been informed by them that nearly all the gold found in the rock, 

 or sand diggings, however small the particles, is covered with an oxyde of 

 iron, or some other foreign substance, that adheres to the particles and 

 prevents their amalgamation with quicksilver ; and that but a small amount, 

 less than fifty, and in some cases, not twenty-five per cent, is saved. 



This arises from the defective means heretofore known and used by those 

 engaged in mining operations, and had led my oldest son to apply his in- 

 ventive and mechanical genius to the discovery of the means to remedy the 

 existing defects, in which he thinks he has proved successful, by perfecting 

 a machine that removes the substances with which the particles of gold are 

 covered, combining with that process a bath of quicksilver with which it is 

 amalgamated. 



A model of this machine was sent to me with the view of obtaining a 

 patent for it. The model was contained in a tin box that would hold about 

 a pint, about half of the space taken up by the model, the balance contained 

 about a pound of gold quartz rock, in small lumps of about an inch in size • 

 some of the lumps exhibited no external signs of containing gold, and«I felt 

 a curiosity to leara how rich the California quartz was. Having a friend 

 engaged in the Assay Office, in Wall street, I applied to him to do me the 

 favor of having the gold it contained extracted. My favor was granted, 

 though at the time I had no hope that more than fifty cents could be ob- 

 tained from so small a quantify of the rock. 



I called t« learn the result of my experiment, and I was surprised when 

 any friend presented me with a lump of what he said was pure gold, and 



