Open a box of caviare two hours before you are to use it, and turn into a china or stone-ware vessel, to rid it of the airless taste and smell imparted by the can. Half-an-hour or so before serving, beat into it the juice of a lemon and two tablespoon-fuls of olive oil until it is like thick cream. Have ready thin slices of buttered bread an inch and a half wide and a little over three inches long. Spread the caviare mixture upon the buttered side of one slice and lay the other upon it as with sandwiches. When all are prepared, pile the bars neatly upon a cold plate, and cover with a napkin until they are sent to table.