104 



should be said these have Dot since been accorded that systematic in- 

 quiry which, otherwise, they would have deserved. 



As decolorizers of saccharine liquors, either dilute or concentrated, 

 certain brown coals are, on the other hand, surprisingly effective. In 

 the table annexed are given to the nearest per cent, the color repeatedly 

 removed from defecated juices, by varying percentages of the article 

 furnished by your Department, referred in each series to standard sam- 

 ples prepared from the defecated juice dealt with by mere passage 

 through filter paper. This paper filtration is a necessity, since suspended 

 matter, lighter in color than the mother- liquor, partially by preventing 

 the transmission of light through this last and partly by itself reflecting 

 light, gives invariably, in simply subsided juices, a tint too light by a 

 number of degrees. The percentages of color removed were uniformly 

 measured by the relative length of columns made to give the same tint 

 as the untreated standard when contained in tubes of like glass, of 

 caliber such as to avoid a decided meniscus, and with light of equal in- 

 tensities transmitted from below in lines parallel to the columns' longi- 

 tudinal axes. 



In the foregoing the juices were treated nearly to neutrality with 

 lime alone. With sulphurous and phosphoric acids, acid albumen, acid 

 sulphite of alumina, or even a decidedly acid lime defecation, the per- 

 cents. removed were, of course, reduced, there being a less intense pri- 

 mary tint. No other lignite gave such high effects as that furnished 

 by your Department. This will be seen from the accompanying approx- 

 imations, obtained with from 22.5 per cent, to 25.0 per cent, of lignite 

 on the weight of sucrose filtered, expressed iu maxima and minima to 

 the nearest 10, sulphur fumes having been used on the juices tL? sir-, 

 ups not having been treated with coal prior to concentration. 



