3\2 On the ^Manufacture of Atuscoiado Si/gar. 



to the sugar, is yet incompetent to the extiication of all ther 

 herbaceous matter, so that it shall be separable by yawing or 

 subsidence : and an excess of lime, not greater than .jo'oo ^^^ 

 or -j-'o^dth of the weight of the juice, is constantly attended 

 with a manifest debasement of the colour of the sugar, 

 when this excess takes place in the beginning of the boiling, 

 or previous to the reduction of the juice by evaporation. It 

 is of no practical use to inquire after every agency by which 

 the excess of lime has these effects ; but it is expedient to 

 observe, that when a juice is yawed with excess of lime, and 

 cleared to. transparcney by subsidence, which soon takes 

 place in a specimen quickly cooled in a wine-glass, it will 

 show colour approaching to that of porter ; while the like 

 juice, treated in the same way, but with only a moderate 

 dose of temper, will be almost colourless when transparent. 

 It is moreover to be observed in ordinary practice, that 

 when too much temper has been used in the yawing, the 

 liquor, during the boiling of the teaches, looks much 

 browner than that which has been less tempered. The 

 scum has a darker colour, and is more apt to break and 

 sink into the liquor j and it has less of the tenacity and floc- 

 culenee by which ordinary scum clings on the skimming 

 instrument, and is separable by the connnon process. 



The practical inference from all these facts is, that the 

 temper ought to be used sparingly in the raw juice in the 

 iperation of yawing, although it should be found necessary 

 to use more temper afterwards, for purposes diflerent from 

 those lately recited. 



It is chiefly by reason of the agency of the temper on the 

 melasses acid, or on that matter which most powerfully im- 

 pedes the separation of the sugar from the melasses mother- 

 liquor, that the temper is eminently useful in the manufac- 

 ture of Muscovado sugar, and that greater quantities of it 

 may be advantageously employed, provided tlie whole of it 

 be not administered at once, and at the period of the manu- 

 facture in which it is apt to colour the juice,' to lessen the 

 buoyancy and tenacity of the scum, and to frustrate the 

 labour of the skimmer. Among the signs which may guide 



