REPORT OF THE CHEMIST.

For purpose of further comparison the following analyses of sugar cenes and juice of the sugar-cane grown in Madras, India, are given below. The canes were divided into upper, middle, and lower thirds, each third being 2 feet in length, except the lower thirds of the selected canes, which were 3 feet in length.

For more clearly presenting the facts developed by the examinations of the four kinds of sorghum, the following chart represents graphically the foregoing results:

It will be observed how closely the Early Amber and Liberian correspond in their development, being almost identical, and yet being clearly distinct varieties. It will also be seen that while these two varieties attain a content of sugar in their juices equal to the average content in the juice of sugar cane by the middle of August, the Chinese does not reach this condition until the last of September, while the Honduras does not reach this point until the middle of October.

It will be seen also that after having attained approximately the maximum content of sugar, this condition is maintained for a long period, affording ample time to work up the crop.

It is doubtless true that had the season been longer it would have been found that the Chinese and Honduras, having once attained this full development of sugar, would also have retained it; but, as is seen by the chart, the heavy frosts and subsequent warm weather which happened about November 24 caused a rapid diminution of sucrose in each variety, and a corresponding increase in glucose.

The converse of what is found true of the sucrose is clearly shown as to the development of the glucose, and it is seen that a minimum quantity once attained is continued a long time, and that this minimum is quite as low as the average amount found present in the sugar-canes. It is obvious that the results depicted upon the chart are not to be taken as entirely exact, but the general fact represented is without doubt true, and with a still larger number of observations the approach to true curves would be found nearer than here represented.

The line representing the average per cent. of sucrose in sugar-beets

is from the results of analysis of thirteen specimens of sugar-beets grown upon the agricultural college farm, Amherst, Mass., and analyzed by Professor Goessmann (vide Mass. Agric. Rept., 1870-71).

An average of all the examinations made of these four sorghums during these periods when they were suitable for cutting gives the following results:

Early Amber, from August 13 to October 29 inclusive, 15 analyses, extending over 78 days, 14.6 per cent. sucrose.

Liberian, from August 13 to October 29 inclusive, 13 analyses, extending over 78 days, 13.8 per cent. sucrose.

Chinese, from September 13 to October 29 inclusive, 7 analyses, extending over 46 days, 13.8 per cent. sucrose.

Honduras, from October 14 to October 29 inclusive, 3 analyses, extending over 16 days, 14.6 per cent. sucrose.

Besides the investigations above mentioned, there have been made 35 experiments in making sugar from corn-stalks, sorghums, pearl millet, &c., in all of which there have been used over 23 tons of stalks. The result of these experiments has been to fully confirm all the experiments not only of the previous year, but also to help towards the solution of certain questions of the highest practical importance. In every case it has been found that the quality of the sirup obtained has been precisely such as the previous analysis in the laboratory of the juice used made probable. An average of the nine best sirups obtained showed a percentage of cane-sugar present equal to 92.7 of the amount originally present in the juice, while an average of the nine poorest (i. e., containing the lowest percentage of cane-sugar) showed a percentage of cane. sugar present equal to 90.1 of the amount present in the juice.

This must not be understood to mean that there has been no loss of sugar in the process of manufacture, as such conclusion would be quite erroneous, as will be seen by consulting tables further on in this report. Below are given the detailed results of 33 experiments in the making of sirups from sorghum, pearl millet, and corn-stalks, and analyses of the juices from which these sirups were made. These stalks were obtained from neighboring farmers, and, as will be seen, were never in the con dition best suited for working, but the results obtained from them are, however, of great practical value, and are given in detail.

The last column represents the relative loss of sucrose in making sirup, as compared with the glucose present, but gives no indication as to the absolute loss which may have been incurred, and since the economical production of sugar largely depends upon the amount of this loss, this matter is discussed more fully in another place.

The apparatus used in the experiments, besides a few barrels and pails for holding the juice, consisted of a copper tank of the following dimensions: 4 feet 3 inches long, 2 feet 3 inches deep, 2 feet 3 inches wide; a galvanized iron pan 9 feet long, 8 inches deep, 3 feet 6 inches wide. This iron pan was surrounded by a wooden frame of 2-inch plank so as to support the sides, and each pan was placed in brickwork with chimney, and so arranged as to permit a fire to be kept below it in direct contact with the bottom. In the case of the copper tank the flames played about the sides also, so as to heat the contents more rapidly. The galvanized iron pan was such as could readily be constructed by any ordinary tinsmith or mechanic. The copper tank was used for defecation with lime; the galvanized iron pan for evaporation. The process, in brief, is as follows: After topping and stripping the corn or sorghum, it was passed through the mill, and when sufficient juice had been obtained it was heated in the copper tank to a temperature of 82° C. 180° F. After the juice had reached this temperature, there was added to it, with stirring, cream of lime, until a piece of litmus paper dipped in the juice showed a purple or bluish-purple color. The heat was now raised to the boiling point, and, so soon as the juice was in good ebulition, the fire was drawn and a thick scum removed from the surface of the juice. After a few minutes the sediment from the juice subsided, and by means of a siphon the clear liquid was decanted off, leaving a muddy sediment which was equal to abont one-tenth to one-twentieth of the bulk of the juice. It was found that by means of the stop-cock at the bottom of the defecator, it was possible to draw off the clarified juice more thoroughly than by means of the siphon, so that this method has been adopted for removing the juice. It is only neces sary to collect in a separate vessel the first portions of juice coming from the stop-cock, which are turbid, and passing these through the bag filter with the sediment. This muddy sediment was then drawn off by means of a stop-cock and filtered through a plaited-bag filter, and the clear filtrate therefrom was added to the liquid previously siphoned off. The clarified juice, which, during the above operation, is not allowed to cool below a temperature of 66° C. or 150° F., was now emptied into the evaporating pan, and there was added to it, with stirring, a solution of sulphurous acid in water until the lime present was neutralized, as was shown by the reddening of litmus paper when it was dipped in the juice. The evaporation was now hastened as much as possible, and the juice concentrated to a sirup at a boiling point of 1129 C., equal to 234° F. or thereabouts. During the close of the evaporation there is great danger of scorching the sirup, and this was obviated by allowing only coals beneath the evaporator and briskly stirring the sirup by means of paddies 8 or 10 inches wide. When the sirup reached the density above indicated it was drawn off into wooden tubs, the fire having previously been drawn from beneath the evaporator.

It is doubtless true that many failures result in securing a crystallizable sirup even from good juice, owing to the operations of pressing of the cane, defecation, and evaporation being too much protracted. In order that those wishing to enter upon this industry may know what is practically attainable, even with common appliances, the following data

are given:

In experiment No. 3, 2,107 pounds of topped stalks of Early Amber cane were pressed by the mill in 34 hours, yielding 975 pounds of juice. The time required for heating the juice, defecation with lime, and evaporation to sirup was 5 hours. In order that the inferior character of the material supplied for these experiments might be known, speci.