Break up the junket tablet into small pieces, and put them into a tablespoonful of water to dissolve. Put the sugar into the milk with the vanilla, and stir till it is dissolved. Warm the milk a little, but only till it is as warm as your finger, so that if you try it by touching it with the tip, you do not feel it at all as colder or warmer. Then quickly turn in the water with the tablet melted in it, stirring it only once, and pour immediately into small cups on the table. These must stand for half and hour without being moved, and then the junket will be stiff, and the cups can be put in the ice-box. In winter you must warm the cups till they are like the milk. This is very nice with a spoonful of whipped cream on each cup, and bits of preserved ginger or of jelly on it.