| | | | | | | Total . . . . . . . . . . . . |100.0|100.0|100.0|100.0|100.0|100.0|100.0 _______________________________|_____|_____|_____|_____|_____|_____|_____ [_Note_. Diets I, III and X have been practically discontinued at the present time. Diets II, V and XI are standard. For data on salt mixtures see Osborne, T. B. and Mendel, J. B. The inorganic elements in nutrition, Jour. Biol. Chem. 1918, xxxiv, 131.] _Salt mixture I (after Rohman)_ _grams_ Ca_3(PO_4)_2 . . . . . 10.00 K_2HPO_4 . . . . . . . 37.00 NaCl . . . . . . . . . 20.00 Na citrate . . . . . . 15.00 Mg citrate . . . . . . 8.00 Ca lactate . . . . . . 8.00 Fe citrate . . . . . . 3.00 ______ Total . . . . . . . . 100.00 _Artificial protein-free milk_ _grams_ CaCO_3 . . . . . . . . 134.8 MgCO_3 . . . . . . . . 24.2 Na_2CO_3 . . . . . . . 34.2 K_2CO_3 . . . . . . . . 141.3 H_3PO_4 . . . . . . . . 103.2 HCl . . . . . . . . . . 53.4 H_2SO_4 . . . . . . . . 9.2 Citric acid: H_2O . . . 111.1 Fe citrate: 1.5H_2O . . 6.34 KI . . . . . . . . . . 0.020 MnSO_4 . . . . . . . . 0.079 NaF . . . . . . . . . . 0.248 K_2Al_2(SO_4)_2 . . . . 0.0245 [N.B.--The ingredients of the artificial protein-free milk are mixed as follows: Making proper allowance for the water in the chemicals the acids are first mixed and the carbonates and citrates added. The traces of KI, MnSO_4, NaF, and K_2Al_2(SO_4)_4 are then added as solutions of known concentration. The mixture is then evaporated to dryness in a current of air at 90 to 100° Centigrade and the residue ground to a fine powder.] _e_. When brewers' yeast is used as a source of the "B" vitamine it is first dried over night in an oven at 110°C. and then subjected to the same purification process as the casein and the starch to remove all trace of the "A."