Proportional dialysis unit
FIG. 1 is a front perspective view of the proportional dialysis unit, showing our new design; 
     FIG. 2 is a rear perspective view of the instrument of FIG. 1; 
     FIG. 3 is a front elevation of the instrument of FIGS. 1 and  2; and 
     FIG. 4 is a side elevation of the instrument of FIGS. 1-3.