808 THE POPULAR SCIENCE MONTHLY. 



The quantity of gold used in the arts, in interior and exterior 

 decorations, in photography, electro-gilding, water-gilding, the orna- 

 mentation of china, etc., is very large, and the greater part is practi- 

 cally lost. Jewelers' sweepings from the floors of the workshops are 

 carefully collected, and even the clothes of the workmen are generally 

 saved and sent to the refiner. After a large gold coinage at the Royal 

 Mint, there is always a great deficiency in waste and sweep. The 

 sweep is composed of cinders or dust from the forge, the sweepings of 

 the workshops, broken crucibles, the dross which adheres to the ingots 

 of metal after fusion, and of every waste which can possibly contain 

 minute particles of the metal. This is generally sold. The silver and 

 gold from photographers' waste is also now carefully collected, and 

 forms a considerable item of economy. A method of utilizing the 

 waste of gold-leaf, used in printing and the arts, is by converting it 

 into what is called fleece-gold. The composition is used like the ordi- 

 nary bronze, except that rather more copal is mixed with it. It is 

 used for all fancy papers for which gold-leaf and bronze have hitherto 

 been used. 



The waste of the glass-furnaces such as pieces of broken glass, 

 flaw-glass, the hearth-droppings, and the glass remaining adherent to 

 the blower's pipe is utilized again, serving a purpose in the manufac- 

 ture of glass, similar to rags in paper-making. Agate glass is made 

 by melting waste pieces of colored glass. One to two thousand tons 

 of cullet, or broken glass, are collected in the metropolis alone, and 

 sold to the few city glass-works to be remelted. Broken bottles are 

 now collected and utilized. Thousands of tons of these are broken 

 every year in London alone. Broken " wines " and broken " sodas " 

 are converted to many useful purposes, the latter especially. The 

 broken bottles are utilized for the manufacture of cheap jewelry, 

 chimney-ornaments, and inferior household glass for the manufactur- 

 ing districts. They are also used for the manufacture of emery- 

 powder, glass paper, etc. Some idea of the number of " sodas " broken 

 in the process of filling, corking, cleaning, and distributing may be 

 gathered from the circumstance that one great mineral-water manu- 

 facturer in London sold last year one hundred tons. The value of the 

 " metal," as it is styled, is somewhere about ten shillings per ton, but 

 it varies according to the demand. When the market for " fancy 

 goods " is active, broken bottles command a better price. A revival 

 of trade sets this particular industry in motion along with others, and 

 broken bottles are enhanced in value. In fact, broken glass and broken 

 pottery serve many purposes, though it is only lately that economic 

 science has learned how to turn them to account. 



The utilization of blast-furnace slag is not new, but has made great 

 progress. Scattered throughout the iron-making districts of Great 

 Britain arc many million tons of scoria or refuse from the blast- 

 furnaces, which is technically known as " slag." This slag goes on accu- 



