MECHANICS AND USEFUL ARTS. 101 



compartments. It is then drawn from the congealer by the pump 

 and forced back again into the distributer in a condensed form. 

 During the process of condensation it gives off its heat to water 

 surrounding a coil through which the gas is passed on its way to 

 the distributer, from which it again passes to the congealer, and 

 so on, being used over and over without material loss. 



It will be obvious that any other volatile liquid besides ammo- 

 nia might be used in the same manner as a conveyer of heat. 



It is further obvious that by replacing the hollow partitions of 

 the congealer by a series of bent pipes, air might be cooled if 

 forced through the series of pipes by a fan. This is precisely 

 what is done with an apparatus made by the proprietors of the 

 Tellier machine, the cool air being supplied to vaults and rooms 

 used for preserving fruits, packing meats, etc., and for purposes" 

 of ventilation in churches and public buildings in hot weather. 

 There is, we are informed, no difficulty in reducing and main- 

 taining the temperature to any desired point down to 32 Fah., 

 and the air, being supplied in a dry state, is much better adapted 

 to keeping fruits and meats than when charged with vapor from 

 its passage through ice. Scientific American. 



NEW SUGAR-REFINING PROCESS. 



In the sugar-house of Messrs. A. Sommier & Co., of Paris, 

 200,000 pounds of raw sugar have for a year past been daily 

 refined according to a process invented by Boivin and Loiseau. 

 The process is founded upon the use of a new body, the sucrate 

 of the hydro-carbonate of lime, which the inventor employs for 

 the purification of raw sugar instead of blood, bone-black, etc. 

 For the preparation of this compound, milk of lime is made from 

 the waste sweet liquors of the refinery, and enough syrup added 

 to give the mixture 20 Baume. This is well agitated and run 

 through a cooler until the temperature sinks to 68 Fah. From 

 the agitators the liquid flows into vats, where it is partially satu- 

 rated with carbonic acid ; the gas is passed through until the 

 desired precipitate of su^ar, lime, and carbonate of lime settles 

 as a gelatinous mass. Alter the purifying agent has been thus 

 prepared, it is applied in the following manner : 



The raw sugar is dissolved in a c}'lindrical pan, similar to a 

 vacuum pan, under diminished pressure. Revolving buckets 

 carry it into receivers over the boilers, and from these it is per- 

 mitted to flow into the boilers, where it conies in contact with the 

 sacro-carbonate of lime previously introduced, in a quantity pro- 

 portional to the percentage of raw sugar. They generally take 

 about 650 gallons of the gelatinous sucro-carbonate to 8,000 

 pounds of sugar. Water is added if necessary ; the whole is 

 boiled, and in this way the solution and clarification are simul- 

 taneously accomplished. One great advantage of the operation 

 is that when syrup is boiled in presence of lime, ammonia is 

 evolved, all glucose is decomposed, and anything likely to pro- 

 duce fermentation is destroyed. 





