On the Manufacture of Muscovado Sugar. 315 



workmen, to whom these pages may ultimately be commu- 

 nicated. 



When a foul liquor is passed through a fine wire sieve, 

 or through a blanket, which stops the coarse filth, but not 

 the finer, and where the liquor so treated still remains 

 clouded or turbid, this is called straining : but when a me- 

 dium, such as close cloth or unsized paper, is used, and this 

 stops all extricated filth and passes the liquor transparent, 

 the process is called Jillration, 



In the refineries in Europe a blanket serves as a filter, 

 but not before the filth of the solution of Muscovado sugar 

 has been entangled in flocks of coagulated ox blood, too 

 large to pa53 through the interstices of a blanket. 



The use of such a woollen strainer has been tried in this 

 island, but is generally abandoned for good reasons. 



A blanket only stniins the boiled catie-juice, while it 

 passes with the velocity necessary for the manufacture of 

 srood Muscovado sugar. When the interstices of the blan- 

 ket are narrowed by coarse flocculcnt filth, and when it be- 

 gins to filtrate truly, the process becomes so slow as to re- 

 tard the manufacture intolerably : the last portions refuse to 

 pass through ; the quantity of sweets retained in and on a 

 large thick blanket makes a great defalcation from the sugar, 

 and the cleansing of the cloth is laborious. 



To make the process of filtration applicable in the manu- 

 facture of Muscovado sugar, it was necessary that a medium 

 should be employed capable of filtrating truly at the begin- 

 ning. It was equally necessary that the velocity of this fil- 

 tration should be equal to that with which the liquor would 

 pass turbid through a coarse strainer of the same dimen- 

 sions. It was moreover requisite, for the reasons above 

 mentioned, that this rapid filtration should be confined to 

 thai period in which all the herbaceous matter is thrown out 

 of solution, and in which the hquor is viscid with sugar. 



These desiderata are attained in the invention lately pre- 

 sented under trial to as many of the honourable members of 

 the appointed committees as could be assembled at the time 

 and place. 



In this first mechanism tlic proof of the principles and 



powers 



