Calculating the solids not fat in the hypothetical case given above by Babcock’s formula, we get t = 8.46, and this plus 3.5 gives 11.96, which is slightly lower than the number obtained by the richmond process.
The babcock formula may be simplified by substituting the number expressing the reading of the quévenne lactometer for that donating the specific gravity, in other words, the specific gravity multiplied by 100 and the quotient diminished by 1000.
The formulas for solids not fat and total solids then become
| t = | L | + 0.2F, and T = | L | + 1.2F, |
| 4 | 4 |
in which L represents the reading of the lactometer. By the addition of the constant factor 0.14 the results calculated by the formula of Babcock are the same as those obtained by the method of Richmond.
In the following table are given the solids not fat in milks as calculated by Babcock’s formula. To obtain the total solids add the per cent of fat to solids not fat. To obtain total solids according to Richmond’s formula increase that number by 0.14.
Table Showing Per Cent of Solids not Fat in Milk
Corresponding to Quévenne’s Lactometer Readings
and Per Cent of Fat.
Per
cent | Lactometer reading at 60° F. |
|---|
| of fat. | 26. | 27. | 28. | 29. | 30. | 31. | 32. | 33. | 34. | 35. | 36 . |
|---|
| 0.0 | 6.50 | 6.75 | 7.00 | 7.25 | 7.50 | 7.75 | 8.00 | 8.25 | 8.50 | 8.75 | 9.00 |
| 0.1 | 6.52 | 6.77 | 7.02 | 7.27 | 7.52 | 7.77 | 8.02 | 8.27 | 8.52 | 8.77 | 9.02 |
| 0.2 | 6.54 | 6.79 | 7.04 | 7.29 | 7.54 | 7.79 | 8.04 | 8.29 | 8.54 | 8.79 | 9.04 |
| 0.3 | 6.56 | 6.81 | 7.06 | 7.31 | 7.56 | 7.81 | 8.06 | 8.31 | 8.56 | 8.81 | 9.06 |
| 0.4 | 6.58 | 6.83 | 7.08 | 7.33 | 7.58 | 7.83 | 8.08 | 8.33 | 8.58 | 8.83 | 9.08 |
| 0.5 | 6.60 | 6.85 | 7.10 | 7.35 | 7.60 | 7.85 | 8.10 | 8.35 | 8.60 | 8.85 | 9.10 |
| 0.6 | 6.62 | 6.87 | 7.12 | 7.37 | 7.62 | 7.87 | 8.12 | 8.37 | 8.62 | 8.87 | 9.12 |
| 0.7 | 6.64 | 6.89 | 7.14 | 7.39 | 7.64 | 7.89 | 8.14 | 8.39 | 8.64 | 8.89 | 9.14 |
| 0.8 | 6.66 | 6.91 | 7.16 | 7.41 | 7.66 | 7.91 | 8.16 | 8.41 | 8.66 | 8.91 | 9.16 |
| 0.9 | 6.68 | 6.93 | 7.18 | 7.43 | 7.68 | 7.93 | 8.18 | 8.43 | 8.68 | 8.93 | 9.18 |
| 1.0 | 6.70 | 6.95 | 7.20 | 7.45 | 7.70 | 7.95 | 8.20 | 8.45 | 8.70 | 8.95 | 9.20 |
| 1.1 | 6.72 | 6.97 | 7.22 | 7.47 | 7.72 | 7.97 | 8.22 | 8.47 | 8.72 | 8.97 | 9.22 |
| 1.2 | 6.74 | 6.99 | 7.24 | 7.49 | 7.74 | 7.99 | 8.24 | 8.49 | 8.74 | 8.99 | 9.24 |
| 1.3 | 6.76 | 7.01 | 7.26 | 7.51 | 7.76 | 8.01 | 8.26 | 8.51 | 8.76 | 9.01 | 9.26 |
| 1.4 | 6.78 | 7.03 | 7.28 | 7.53 | 7.78 | 8.03 | 8.28 | 8.53 | 8.78 | 9.03 | 9.28 |
| 1.5 | 6.80 | 7.05 | 7.30 | 7.55 | 7.80 | 8.05 | 8.30 | 8.55 | 8.80 | 9.05 | 9.30 |
| 1.6 | 6.82 | 7.07 | 7.32 | 7.57 | 7.82 | 8.07 | 8.32 | 8.57 | 8.82 | 9.07 | 9.32 |
| 1.7 | 6.84 | 7.09 | 7.34 | 7.59 | 7.84 | 8.09 | 8.34 | 8.59 | 8.84 | 9.09 | 9.34 |
| 1.8 | 6.86 | 7.11 | 7.36 | 7.61 | 7.86 | 8.11 | 8.36 | 8.61 | 8.86 | 9.11 | 9.37 |
| 1.9 | 6.88 | 7.13 | 7.38 | 7.63 | 7.88 | 8.13 | 8.38 | 8.63 | 8.88 | 9.14 | 9.39 |
| 2.0 | 6.90 | 7.15 | 7.40 | 7.65 | 7.90 | 8.15 | 8.40 | 8.66 | 8.91 | 9.16 | 9.41 |
| 2.1 | 6.92 | 7.17 | 7.42 | 7.67 | 7.92 | 8.17 | 8.42 | 8.68 | 8.93 | 9.18 | 9.43 |
| 2.2 | 6.94 | 7.19 | 7.44 | 7.69 | 7.94 | 8.19 | 8.44 | 8.70 | 8.95 | 9.20 | 9.45 |
| 2.3 | 6.96 | 7.21 | 7.46 | 7.71 | 7.96 | 8.21 | 8.46 | 8.72 | 8.97 | 9.22 | 9.47 |
| 2.4 | 6.98 | 7.23 | 7.48 | 7.73 | 7.98 | 8.23 | 8.48 | 8.74 | 8.99 | 9.24 | 9.49 |
| 2.5 | 7.00 | 7.25 | 7.50 | 7.75 | 8.00 | 8.25 | 8.50 | 8.76 | 9.01 | 9.26 | 9.51 |
| 2.6 | 7.02 | 7.27 | 7.52 | 7.77 | 8.02 | 8.27 | 8.52 | 8.78 | 9.03 | 9.28 | 9.53 |
| 2.7 | 7.04 | 7.29 | 7.54 | 7.79 | 8.04 | 8.29 | 8.54 | 8.80 | 9.05 | 9.30 | 9.55 |
| 2.8 | 7.06 | 7.31 | 7.56 | 7.81 | 8.06 | 8.31 | 8.57 | 8.82 | 9.07 | 9.32 | 9.57 |
| 2.9 | 7.08 | 7.33 | 7.58 | 7.83 | 8.08 | 8.33 | 8.59 | 8.84 | 9.09 | 9.34 | 9.59 |
| 3.0 | 7.10 | 7.35 | 7.60 | 7.85 | 8.10 | 8.36 | 8.61 | 8.86 | 9.11 | 9.36 | 9.61 |
| 3.1 | 7.12 | 7.37 | 7.62 | 7.87 | 8.13 | 8.38 | 8.63 | 8.88 | 9.13 | 9.38 | 9.64 |
| 3.2 | 7.14 | 7.39 | 7.64 | 7.89 | 8.15 | 8.40 | 8.65 | 8.90 | 9.15 | 9.41 | 9.66 |
| 3.3 | 7.16 | 7.41 | 7.66 | 7.92 | 8.17 | 8.42 | 8.67 | 8.92 | 9.18 | 9.43 | 9.68 |
| 3.4 | 7.18 | 7.43 | 7.69 | 7.94 | 8.19 | 8.44 | 8.69 | 8.94 | 9.20 | 9.45 | 9.70 |
| 3.5 | 7.20 | 7.45 | 7.71 | 7.96 | 8.21 | 8.46 | 8.71 | 8.96 | 9.22 | 9.47 | 9.72 |
| 3.6 | 7.22 | 7.48 | 7.73 | 7.98 | 8.23 | 8.48 | 8.73 | 8.98 | 9.24 | 9.49 | 9.74 |
| 3.7 | 7.24 | 7.50 | 7.75 | 8.00 | 8.25 | 8.50 | 8.75 | 9.00 | 9.26 | 9.51 | 9.76 |
| 3.8 | 7.26 | 7.52 | 7.77 | 8.02 | 8.27 | 8.52 | 8.77 | 9.02 | 9.28 | 9.53 | 9.78 |
| 3.9 | 7.28 | 7.54 | 7.79 | 8.04 | 8.29 | 8.54 | 8.79 | 9.04 | 9.30 | 9.55 | 9.80 |
| 4.0 | 7.30 | 7.56 | 7.81 | 8.06 | 8.31 | 8.56 | 8.81 | 9.06 | 9.32 | 9.57 | 9.83 |
| 4.1 | 7.32 | 7.58 | 7.83 | 8.08 | 8.33 | 8.58 | 8.83 | 9.08 | 9.34 | 9.59 | 9.85 |
| 4.2 | 7.34 | 7.60 | 7.85 | 8.10 | 8.35 | 8.60 | 8.85 | 9.11 | 9.36 | 9.62 | 9.87 |
| 4.3 | 7.36 | 7.62 | 7.87 | 8.12 | 8.37 | 8.62 | 8.88 | 9.13 | 9.38 | 9.64 | 9.89 |
| 4.4 | 7.38 | 7.64 | 7.89 | 8.14 | 8.39 | 8.64 | 8.90 | 9.15 | 9.40 | 9.66 | 9.91 |
| 4.5 | 7.40 | 7.66 | 7.91 | 8.16 | 8.41 | 8.66 | 8.92 | 9.17 | 9.42 | 9.68 | 9.93 |
| 4.6 | 7.43 | 7.68 | 7.93 | 8.18 | 8.43 | 8.68 | 8.94 | 9.19 | 9.44 | 9.70 | 9.95 |
| 4.7 | 7.45 | 7.70 | 7.95 | 8.20 | 8.45 | 8.70 | 8.96 | 9.21 | 9.46 | 9.72 | 9.97 |
| 4.8 | 7.47 | 7.72 | 7.97 | 8.22 | 8.47 | 8.72 | 8.98 | 9.23 | 9.48 | 9.74 | 9.99 |
| 4.9 | 7.49 | 7.74 | 7.99 | 8.24 | 8.49 | 8.74 | 9.00 | 9.25 | 9.50 | 9.76 | 10.01 |
| 5.0 | 7.51 | 7.76 | 8.01 | 8.26 | 8.51 | 8.76 | 9.02 | 9.27 | 9.52 | 9.78 | 10.03 |
| 5.1 | 7.53 | 7.78 | 8.03 | 8.28 | 8.53 | 8.79 | 9.04 | 9.29 | 9.54 | 9.80 | 10.05 |
| 5.2 | 7.55 | 7.80 | 8.05 | 8.30 | 8.55 | 8.81 | 9.06 | 9.31 | 9.56 | 9.82 | 10.07 |
| 5.3 | 7.57 | 7.82 | 8.07 | 8.32 | 8.57 | 8.83 | 9.08 | 9.33 | 9.58 | 9.84 | 10.09 |
| 5.4 | 7.59 | 7.84 | 8.09 | 8.34 | 8.60 | 8.85 | 9.10 | 9.36 | 9.61 | 9.86 | 10.11 |
| 5.5 | 7.61 | 7.86 | 8.11 | 8.36 | 8.62 | 8.87 | 9.12 | 9.38 | 9.63 | 9.88 | 10.13 |
| 5.6 | 7.63 | 7.88 | 8.13 | 8.39 | 8.64 | 8.89 | 9.15 | 9.40 | 9.65 | 9.90 | 10.15 |
| 5.7 | 7.65 | 7.90 | 8.15 | 8.41 | 8.66 | 8.91 | 9.17 | 9.42 | 9.67 | 9.92 | 10.17 |
| 5.8 | 7.67 | 7.92 | 8.17 | 8.43 | 8.68 | 8.94 | 9.19 | 9.44 | 9.69 | 9.94 | 10.19 |
| 5.9 | 7.69 | 7.94 | 8.20 | 8.45 | 8.70 | 8.96 | 9.21 | 9.46 | 9.71 | 9.96 | 10.22 |
| 6.0 | 7.71 | 7.96 | 8.22 | 8.47 | 8.72 | 8.98 | 9.23 | 9.48 | 9.73 | 9.98 | 10.24 |
449. Determination of Ash.—In the determination of the solid residue obtained by drying milk, it is important to observe the directions already given ([28-32]).
In the direct ignition of the sample, a portion of the sulfur and phosphorus may escape oxidation and be lost as volatile compounds. This loss may be avoided by the use of proper oxidizing agents or by conducting the combustion as heretofore described.[430] In the official method, it is directed to add six cubic centimeters of nitric acid to twenty of milk, evaporate to dryness and ignite the residue at a low red heat until free of carbon.[431] It is doubtful if this precaution be entirely sufficient to save all the sulfur and phosphorus, but the method is evidently more reliable than the common one of direct ignition without any oxidizing reagent whatever.