By consulting the table it will be seen that the vertical column headed
I = 150 is nearest to Z, 145, the horizontal column headed 95: 5 is
nearest to the ratio of R to I, 95.1: 4.9. Where these columns meet we
find the factor 51.2, which enters into the final calculation:
CuF .290 × 51.2
----- = ------------- = 4.56 the true per cent of invert sugar.
W 3.256
MEISSL AND HILLER’S FACTORS FOR THE DETERMINATION OF
MORE THAN ONE PER CENT OF INVERT SUGAR.
Ratio of Approximate absolute weight of invert sugar = _Z_.
sucrose I = I = I = I = I = I = I =
to invert 200 175 150 125 100 75 50
sugar = mg. mg. mg. mg. mg. mg. mg.
R : I.
0 : 100 56.4 55.4 54.5 53.8 53.2 53.0 53.0
10 : 90 56.3 55.3 54.4 53.8 53.2 52.9 52.9
20 : 80 56.2 55.2 54.3 53.7 53.2 52.7 52.7
30 : 70 56.1 55.1 54.2 53.7 53.2 52.6 52.6
40 : 60 55.9 55.0 54.1 53.6 53.1 52.5 52.4
50 : 50 55.7 54.9 54.0 53.5 53.1 52.3 52.2
60 : 40 55.6 54.7 53.8 53.2 52.8 52.1 51.9
70 : 30 55.5 54.5 53.5 52.9 52.5 51.9 51.6
80 : 20 55.4 54.3 53.3 52.7 52.2 51.7 51.3
90 : 10 54.6 53.6 53.1 52.6 52.1 51.6 51.2
91 : 9 54.1 53.6 52.6 52.1 51.6 51.2 50.7
92 : 8 53.6 53.1 52.1 51.6 51.2 50.7 50.3
93 : 7 53.6 53.1 52.1 51.2 50.7 50.3 49.8
94 : 6 53.1 52.6 51.6 50.7 50.3 49.8 48.9
95 : 5 52.6 52.1 51.2 50.3 49.4 48.9 48.5
96 : 4 52.1 51.2 50.7 49.8 48.9 47.7 46.9
97 : 3 50.7 50.3 49.8 48.9 47.7 46.2 45.1
98 : 2 49.9 48.9 48.5 47.3 45.8 43.3 40.0
99 : 1 47.7 47.3 46.5 45.1 43.3 41.2 38.1
=143. Table for the Estimation of Milk Sugar.=—The solutions to be used
for this table are the same as those employed in the preceding table
for the estimation of invert sugar. The milk sugar is supposed to be in
a pure form in solution before beginning the analysis. The method to be
employed for milk will be given in the part devoted to dairy products.
In the conduct of the work twenty-five cubic centimeters of the copper
solution are mixed with an equal quantity of the alkaline tartrate
mixture, and from twenty to one hundred cubic centimeters of the sugar
solution added, according to its concentration. This solution should
not contain less than seventy nor more than 306 milligrams of lactose.
The volume is completed to 150 cubic centimeters with boiling water and
kept in lively ebullition for six minutes. The rest of the operation is
conducted in the manner already described. From the weight of copper
obtained the quantity of milk sugar is determined by inspecting the
table. It is recommended to use such a weight of milk sugar as will
give about 200 milligrams of copper.