296 Transactions of tiie State Agricultural Society. 



understood. The whole hulk of gas passing out of the last condenser 

 is saturated with mercurial vapor. The amount of metal contained in 

 this vapor depends on the temperature, and for low temperatures is 

 very small per cubic foot, hut its aggregate amount per day is by no 

 means inconsiderable. Another source of loss is the tine dust of mer- 

 cury suspended in the gas, minute globules, so small that they fall very 

 slowly through the air, and are, therefore, carried away in the current 

 of gas. The rate at which a spherical body falls through the air 

 depends upon its specific gravity and its size, and we have, therefore, 

 only to make a globule small enough to give it a permanent velocity of 

 ten feet, or of one foot, per second. As the mercurial vapor is cooled in 

 the condensers, the mercury is separated out like mist, and the indi- 

 vidual globules, which are too small to fall rapidly, and which do not 

 collide and aggregate with others, are, to a great extent, carried off as a 

 dust. Nothing is more difficult than to filter very fine dust effectually 

 on a large scale from a current of gas, as has been proved over and 

 over again in the attempts made to catch the fume from silver smelting 

 furnaces. How much such fume is formed in quicksilver smelting must 

 depend on various circumstances, but the formation of soot in the con- 

 ducters is sure to be accompanied by a loss in this way, for the metal 

 which is separated out at the same time as the soot will, to some extent, 

 be coated by non-metallic impurities, and rendered incapable of running 

 together into larger drops. 



The metallic mercury obtained from the conducters rarely needs any 

 refining. Dirt mixed with it is readily extracted by filtering through 

 cloth or leather, and it is then simply weighed out, and bottled up in 

 wrought iron flasks ready for market. 



The metallurgy of quicksilver is thus, as you perceive, comparatively 

 simple, consisting essentially of but a single, and by no means compli- 

 cated, process. The working of quicksilver ores is unquestionably 

 susceptible of great improvements, but it is only lately that a sufficient 

 number of cinnabar mines have been known to give employment to 

 more than an exceedingly small number of technologists. In the future 

 emulation and competition will probably produce rapid advances. I 

 shall finisnh the hour with a few remarks on 



FUEL. 



Mr. Becker occupied the second half of the hour with remarks on 

 fuel, in which he took occasion to point out the causes of and the 

 remedy for the ignition of coal cargoes, and laid especial stress on the 

 great advances made on technology in the introduction of gas, made 

 from inferior fuels, or even from wet sawdust, for producing tempera- 

 tures hitherto unattainable. 



