Repository: UIHistories Project: Board of Trustees Minutes - 1882 [PAGE 89]

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83

ANALYSIS OF SORGHUM S E E D .

A sufficient quantity of the seed was ground as fine as possible in an iron mortar, and was preserved in a glass-stoppered bottle. The following portions of the ground seed wer,e taken: 10 grams, for the estimation of sugar, dextrine, starch and fiber. 1 gram ; " " water and ash. 1 " " " albuminoids/ 1 " " " oil. 1 " " " tannin. Sugar, etc.—The ten grams reserved for sugar, etc., were rubbed up thoroughly with water in a mortar, then transferred to a filter and washed well with water. Solution=A. Besidue=B. The solution, A, was concentrated to about 10 c.c. in a porcelain dish on a water bath, then transferred into a strong prescription bottle and washed wTith about 10 c.c. of water, and the washings added. 5 c.c. of normal sulphuric acid were added, the bottle closed with a rubber stopper securely tied. The bottle and its contents were then transferred to a salt bath and boiled for six hours. After cooling, the contents of the bottle were transferred to a graduated cylinder, neutralized and diluted to 100 c.c, the coloring matter precipitated with acetate of lead, and, after thoroughly mixing, the whole was allowed to stand until the precipitate had settled to the bottom. A portion of the clear liquid was then transferred to a burette and dropped into 10 c.c. of Pehling's solution, diluted four times, and at the boiling temperature, until the whole of the copper had been precipitated as cuprous oxide. This point was determined by filtering a small quantity from time to time, acidifying the filtrate with acetic acid, and testing for copper with ferro-cyanide of potassium. The number of c.c of the sugar solution it took was noted, and the sugar and dextrine determined by the following proportion : 1. The number of c.c. it took to precipitate copper solution: total number of c.c. : : .05 (grams of grape sugar required to precipitate 10 c.c. of Fehling's solution) : x. X multiplied by 0.95 will give the grams of sugar in 10 grams of seed. The residue, B, was washed on the filter with alcohol acidulated with sulphuric acid and finally with water, to dissolve the gluten. Then the residue was washed off the filter into a beaker diluted to about 400 c.c, 5 c.c of sulphuric acid added, and the whole boiled on a water bath until the liquid had no milky appearance. It was then filtered through an equipoised filter and washed. Solution=C. Besidue==D. Solution C was diluted to 500 c.c. 50 c.c of this solution were transferred to a prescription bottle and then treated as above for sugar and dextrine. Prom the grape sugar obtained, the amount of starch was calculated. Besidue D was boiled with hot sodium hydroxide, again thrown upon the filter and washed with the same solvent; afterwards, with