Bulletin - Bureau of Chemistry - United States. Bureau of Chemistry

in order to obtain a high grade of sugar. The "seconds" polarized as high as the "firsts," and were sold at about the same price. Owing to the fact that after the first few days of the season a small nucleus of "firsts" was left in the pan for the formation of the "seconds," these sugars should both be termed "firsts," and the "thirds" and "fourths” would then be respectively "seconds" and "thirds." The "thirds" and "fourths" were boiled to string proof as usual.

In making these grades of sugar, necessitating a double filtration of the sirup, double the loss was experienced in the bone-black room. The loss of which I now speak is that due to the absorption of sugar by the char and the losses in the waste waters. The filters at Magnolia are of the form termed Dumont or open filters. Owing to the difficulty of properly washing the char, without employing a very large quantity of water, the waste waters contained considerable sugar, as the following table will show:

TABLE XII.-Analyses of waste waters from bone-black room.

These analyses show an enormous loss in the filter room. After November 24 orders were given the filtermen to wash their filters a very considerably longer time than they bad been doing.

Samples were frequently brought to the laboratory for examination, and whenever the proportion of sucrose exceeded .50 the washing was continued. It is impossible to estimate the loss from this source, but it was certainly very large. Under the conditions at Magnolia the past season it was impracticable to vary the mode of work in the boneblack room. The quantity of waste water was variously estimated at from 1,000 to 1,500 gallons per twenty-four hours; this would indicate losses ranging from less than 100 to nearly 300 pounds of sugar per day, or from .5 to 1.5 pounds per ton of cane. As there were no means of ascertaining the exact amount of waste water, these figures are a rough approximation of little value.

THE USE OF SUPERPHOSPHATES.

I have frequently objected to the use of superphosphates of lime and alumina, but it was not until late in November that their use was discontinued. These superphosphates usually contain an excess of the sulphuric acid used in their manufacture, and the stock at Magnolia was no exception to the rule. It is difficult to find any advantage arising from the use of these superphosphates.