Proceedings of the Polytechnic Association. 935 



Teanspoetation of the Sugae Peoduct. 

 Messrs. Rousseau and Bonnaterre's plan of converting the saccha- 

 rine juice of cane or of beet-root into a peculiar saccharate of lime 

 and of transporting salt instead of raw sugar from distant ports 

 to the place where it is to be refined, is soon to be tried on a large 

 scale in some of the French colonies. This compound is very hard, 

 can be kept any length of time, and can be transported with less risk 

 of damage than raw sugar. 



Oee Sepaeatoe. 



Mr. S. E,. Krom exhibited his ore separator or concentrator. Air 

 is intermittently forced through the pulverized ore and causes the 

 lighter particles to rise to the surface, when they overflow into a 

 suitable receptacle, and the heavier particles pass out below in a 

 different direction. The ore is first crushed in jaws, which crack it ; 

 but rollers are afterward used for finer pulverizing. The machine 

 runs about seventy revolutions per minute. It will concentrate 

 about five or six tons a day. The cost of a large machine is $600. 



Mr. Randall remarked that when the sulphates of zinc are acted 

 on by the air bellows, the lighter particles will pass off, and hence 

 the richer parts will be lost. 



Mr. Krom said that the intermittent action of the air obviates 

 much of this difficulty. 



Dr. A. "VV. Hall stated that the silver ores of Kevada and Colorado 

 have to be finely crushed, almost to an impalpable power, in a dry 

 state for chemical treatment, before water touches the material. 

 This requires a separator, different from the one here exhibited, as 

 this can only assort ores coarsely pulverized. To separate the flour 

 ore, as fast as produced by the stamps, has been a difficult problem, 

 and attended with great expense. A patent was recently issued to 

 him for crushing ore by stanii)s or wheels, in an air tight battery, 

 and carrying off" the floured ore, as fast as reduced, by an air blast, to 

 a large inclosed funnel-shaped receiver, where it settles, the heavier 

 particles nearest the bottom, etc. The air escapes through a gauge 

 screen at the top. This, however, was not so much intended to assort 

 the heavier particles as to relieve the crushing of the flour as fast as 

 produced ; by which their efficiency was greatly increased. 



Prof. J. A. "Whitney said that some three years since, Mr. Law- 

 rence Holmes, Jr., now deceased, having his attention called to the 

 separation of the granular iron ore from the so called litanic sand of 



