He's done My Saber is Bentand I Kid You Not. In Three on a Toothbrush, Jack Paar continues in the I/Me vein with six chapters describing trips taken with his wife and young daughter -- usually with cameras along to record the scene in motion. From Russia in '61 to Brazil in '64, his travel journal reports the physical comforts he enjoyed or missed, wise cracks cracked and celebrities deliberately encountered. There was Dr. Schweitzer in Lambarene and Mary Martin on her ranch in Brazil and such are rendered up in the same chatty format as the show without the interruptions for a Bromo Seltzer commercial. Five more essays deal with such matters as the wry discomforts of being Jack Paar, fatherhood and recollections of quotable notables who have appeared on the show. Jack Paar on paper is like Jack Paar on TV -- as bright as a butterfly with about the same attention span, flittering from subject to subject and landing lightly without ever penetrating.