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SELECTED ARTICLES. 
takes place immediately, leaving the liquid clear; 3d, when 
this liquid is but slightly coloured. 
Unfortunately, however, the dose of lime required is very 
variable, according to the season, the nature of the soil in 
which the roots have grown, the mode in which these roots 
have been kept, and finally, according to the time which has 
elapsed since they were gathered ; it therefore varies from half 
a pound to three pounds to the hectolitre (22 gallons) of juice. 
The sedulous attention of the manufacturer may obviate this 
inconvenience, in part, but even the greatest care is sometimes 
ineffectual, because, first, the clarification may take place 
where a sufficient quantity of lime has not been used; second, 
from the same result occurring with an excess of this agent; 
in either case much embarrassment in the subsequent processes 
will ensue. 
If the lime has not been used in sufficient quantity, the 
juice, although but little coloured at first, will become very 
dark when evaporated, and the syrup will acquire great vis- 
cidity; if, on the contrary, an excess of lime has been em- 
ployed, the juice will be light coloured and the syrup of a 
bright yellow, but on concentration, they will become burnt 
if the operation be performed by a naked fire, and will be de- 
teriorated if evaporated by steam. 
The causes of these two accidents have already been ex- 
plained by several manufacturers and chemists; it has been 
shown that beet juice contains a mucilaginous matter, which 
is acted on very rapidly by the air; this is capable of combin- 
ing with the lime and forming a precipitate; if a certain pro- 
portion of this remains in the juice, the syrup will be dark 
coloured as well as viscid. On the other hand, if an excess of 
lime be used, this excess will combine with the sugar and 
form a saccharate of lime; a compound which is very soluble, 
uncrystallizable, and retaining so much water as almost to pre- 
vent any concentration of the syrup. 
Manufacturers have hitherto resorted to but one expedient 
to obviate these drawbacks; this consists in the use of animal 
charcoal. This substance, in fact, possesses not only the 
