STATE AGRICULTURAL SOCIETY. 291 



gradually to the density necessary for crystalization. This operation is 

 divided into two parts; concentration, properly so called, and cooking 

 or baking. It is well known that the boiling point of a liquid in a 

 vacuum is at very much lower temperature than it was when exposed to 

 atmospheric pressure. Upon this principle the application of the 

 vacuum in concentrating and cooking the juice rests. 



The introduction of vacuum boilers is almost the only improvement, 

 in reality, which has been made in the manufacture of sugar for thirty 

 3 r ears, for the elements of all the other improvements which have been 

 made were contained in the old processes. With the apparatus now 

 used, it is impossible to caramelize the syrup, and the cooking or baking 

 may be pushed to crystalization — an operation which is called baking in 

 grains, and which is described at length in the accompanying report; 

 finally, the heat is not sufficient to cause the saccharate alkalies, which 

 have been left in the juice, to produce any reaction of importance. The 

 machines for concentration which have produced the best result are 

 manufactured by MM. Call & Co., and are known as machines of triple 

 effect. 



Crystalization. 



This is usually done in vats. The syrup is exposed to a temperature 

 of from thirty to thirty-five degrees centigrade, which is maintained as 

 uniform as possible till the crystalization is complete. 



The turbine, by means of which the syrup is separated from the 

 crystalized sugar, is a great improvement over the ordinary and older 

 methods. By the use of this machine the purification of the crystals of 

 sugar is reduced to an almost instantaneous mechanical operation. 



The other operations and processes connected with the manufacture 

 of sugar, some of which are recent and some of older date, will be 

 described at length in the accompanying report. At the present time 

 the machinery for a complete and well arranged sugar factory consists 

 of washing machines, rasps, presses — mechanical and hydraulic, boilers 

 of defecation, carbonic acid boilers, carbonic acid generators, foam 

 presses, animal charcoal filters, machines for concentrating and cooking 

 the sugar, crystalizing vats, turbines and furnaces for revivifying the 

 animal charcoal. To this must be added the engines and generators, 

 the size and cost of which depend necessarily upon the extent of the 

 factory. 



Of the improvements which have been made of late years in the 

 methods and processes of manufacturing sugar, M. Constant Say makes 

 the following observations : 



'to 



" Since eighteen hundred and fifty-seven, the manufacture and refining 

 of sugar has made great progress, the result of which is the production 

 of sugar at a lower cost than formerly. The principal improvements 

 in the manufacture are in the process of double carbonation, the appa- 

 ratus of triple effect, of roasting in vacuo, and the use of centrifugal 

 machines." 



The Diffusion Process. 



Mr. Post, Consul of the United States at Vienna, Austria, writes as 

 follows concerning the new diffusion process : 



" The new process recently invented by Mr. Julius Eobert, a sugar 

 manufacturer of Seelowitz, Austria, is working a complete change in the 



