974 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
in other samples, the degree of this exercising an undoubted in-— 
fluence. As was noticed in the matter of purity co-efficient, after the 
use of some 15 per cent. further amounts added were out of all pro- . 
portion to the increase in effect. The power of lignite to absorb or © 
otherwise destroy or remove is apparently confined to those contained 
substances producing particular color effects only. For these its — 
affinity is certainly very great, animal char or bone-black, in the 
lower percentages, being found altogether out of comparison with it 
in. this regard. These colors suppressed, however, by a relatively 
small quantity of the lignite, additional quantities produce but little 
useful effect, the remaining coloring matters being those for which 
it possesses little or no affinity. This hypothesis explains the fact 
that, having used so much as 30 to 45 per cent. to secure rapidity of 
filtration, the cake from one operation was found to haye lost none 
of its decolorizing power upon a second application, though it no 
longer filtered with the same efficiency. Its influence upon the ex- , 
ponent, also, seemed to have diminished little by like previous use 
upon juice, although considerably more so after the filtration of dense 
sirups not first treated as juice, a fact possibly finding its explana- 
tion on the same lines. Except for the Texas sample, all the coals 
“éxamined gave up a slight amount of greenish coloring matter, 
whether boiled in distilled water, juice, or sirup, all showing like- 
wise an acid réaction, your‘own being most pronounced in the latter 
particular. 
A hard and apparently very dry cake was obtained with whatever 
variety of lignite, if employed in amounts above 15 per cent. of the 
contained sugar, provided only ample time was accorded its forma- 
tion. It was, however, in all instances of high percents, exceed- 
ingly porous as compared with scum cake finished off at correspond- 
ing pressures, welghing per press always in close proximity to the 
ascertained average of 670 pounds at a final pressure of 60 pounds, 
of which, after lixiviation at 40 pounds pressure, 49 per cent., a little 
more or less, was moisture. 
Since with a juice polarizing 13 per cent. sucrose some 46 pounds 
of the latter would be otherwise lost from each pressing, equal to 
neirly 3 per cent. of the entire amount treated, supposing 1,300 gal- 
lons of juice to be put through, with 30 per cent. of the brown coal, 
at each operation, the importance of lixiviation can scarcely be over- 
stated. No press except arranged for this supplementary process in 
its most complete attainment would, of course, be admissible. Thais 
work is too uniformly accomplished by steam, by reason of channels 
at- once cut on Tines of least resistance, which, besides, leaves the 
press too hot for immediate manipulation and severely taxes the 
cloths. Hot water results in too rapid and too great a reduction of 
the purity co-efficient, possibly because of the action of heat upon the 
solubility of some among the retained impurities. Cold water cer- 
tainly performed best, all things considered. 
The theoretical amount of so-called displacement water was found 
altogether inadequate. For a 30-frame Kroog press 200 liters are, 
for reasons not necessary to state, supposed to be the extreme limit 
of requirement. This amount when passed in one hour—already a 
serious loss of time compared with the filtration itself, which con- 
sumes but three with 30 per cent. of coal—gave at finishing off a 
sweet water still running at an average analysis of: Solids, 6.77; 
sucrose, 5.0; reducing sugars, 0.52; exponent, 73.87. Assuming the 
