ON THE PURIFICATION OP BEET JUICE, &C. 
155 
his syrup evaporates the best, he should prepare the dilute sul- 
phuric acid; this is done by mixing one part of the acid of 
commerce with twenty parts of water. He may now employ 
as much lime in clarification as he deems expedient. After 
evaporating the syrup until it marks 10°, a trial is to be made 
of it. If it marks more on the alkalimeter, than that ascer- 
tained to be the most advantageous, the dilute sulphuric acid 
is to be added by degrees, so as to reduce the syrup to the 
proper point. 
With a little experience the manufacturer will readily as- 
certain the quantity of acid sufficient to saturate a given weight 
of lime; thus he will find that about a quart of the dilute acid 
will correspond to about a quarter of a pound of lime; so that 
when he is obliged to use an excess of this latter, he will at 
once be aware what additional quantity of acid will be re- 
quired to saturate it. 
An acquaintance with this fact, however, does not preclude 
the necessity of a preliminary trial of the alkalinity of the 
syrup, as this is liable to many changes; hence we have not 
been able to give any precise scale of degrees applicable to 
this syrup, nor attempted to decide in a positive manner with 
regard to the quantity of acid to be employed to a given 
weight of lime, as these must depend on the nature of the 
roots, the season of the year, the time the roots have been 
kept, &c, as well as on the purity of the lime. 
But although we cannot give these data, we are happy in 
pointing r out to the manufacturer a ready method of ascer- 
taining the best proportions of alkali and acid required, and 
thus enabling him to obtain certain and invariable results. 
I will cite an example in point. After having ascertained 
the truth of the above mentioned facts by a series of careful 
experiments, I had occasion to visit a well known manufac- 
tory; on entering it, I was immediately convinced, from the 
smell, that the syrup then boiling was not sufficiently alka- 
line, and was told that the sugar obtained was red and could 
not be bleached. On examining the process, I found that a 
pound of lime was used to each hectolitre of juice, that the 
clarification was apparently perfect, but that the syrup on eva- 
