980 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
Yor sirups from unfiltered juices the ratio of hgnite had, of course, 
to be increased until percentages approaching those employed with 
juice had been attained. Equal amounts would probably have been 
necessary, in terms of sugar, except for scums removed and some 8 
to 10 per cent. of the juice itself already filtered with these, decan- 
tation of clear liquor from skimmings not having been practiced. 
Mere bulk, thus, in the filtrate, was seen to exercise no perceptible 
influence in this work. The dilution of sirup by the addition of 
water in any amount can, of course, In no wise reduce the quantity 
of coal required, which is determined alone by the quantity and 
quality of non-sugar dealt with. Neither the net result in purity nor 
in color was equivalent in filtered sirup from unnltered juice to that 
secured in unfiltered sirups from filtered juice. The glucose ratios 
of sirups first filtered as such were always considerably higher than 
those of unfiltered sirups derived from filtered juices of like quality. 
It is supposed that by the filtration of juice, though this is left in all 
cases more acid by the process, certain active inverting agents are 
removed, thus reducing the losses otherwise sustained in concentra- 
tion. The brown coal also removed an amount of reducing sugars 
relatively larger than that of sucrose lost in the operation, the glu- 
cose ratio being almost uniformly lower after than before filtration, 
whether of juice or sirup. The ash is also reduced. 
Not above 550 gallons of sirup from unfiltered juice could be put 
through a 30-frame Kroog press with 25 per cent. of brown coal on 
the weight of its sucrose at one operation, this, complete, occupying 
about four hours. <A ¢-inch frame or chamber was found ample in 
the treatment of sirups, but even for this work 400-foot presses, it is 
thought, would be preferred. Thinner frames would be necessary 
with reduced percentages of lignite. Lower pressures than those 
mentioned for juice gave the more satisfactory results, which also 
should be extremely steady. 
The cake from sirup filtrations following that of the juice, with or 
without lixiviation, when mixed with the amount of fresh coal neces- 
sary to bring the total of this to the usual standard, was found to 
erform about as well on a fresh supply of juice as an equal total of 
resh coal, the amount of the latter being thus proportionately re- 
duced. In practice this would obviate the difficulty of sweet water 
from the sirup filters. Wood char was given no trial in connection 
with concentrated liquors. The whole subject of sirup filtration in 
filter presses merits more thorough investigation than circumstances 
have yet permitted at this factory, although success with such can 
scarcely supplant the far greater necessity for previous treatment of 
the juices. 
Experiments, by no means exhaustive, were also made with the 
Bauer process. This failed from the first. The mucilaginous im- 
purities, passing through the interstices of the bone char, reached 
and occluded at once the pores of the cloth, thus bringing operations 
to a speedy termination with every trial. The cloths were washed 
with great difficulty. To fully meet every prejudice the entirely in- 
utile use of various fabrics was resorted to. With bone-black, from 
coarse to finest, the result was always the same. Indeed, as is well 
known, animal char in sugar work is an extremely poor filtering 
medium, no matter how skillfully revivified, and except for the pre- 
liminary Taylor or bag filtration could scarcely be used after the 
manner or in the percents at present common except upon the high- 
est centrifugal goods, even in the refining of sugars from which the 
