Explosive Incident

President Franc,ois Mitterrand last week made the first visit to Britain by a French head of state in eight years. Like two of his postwar predecessors, Charles de Gaulle and Valery Giscard d'Estaing, the Socialist leader was accorded the rare honor of addressing members of both houses of Parliament. He used the occasion to issue a ringing appeal for European unity. Said Mitterrand: "The moment has come to make Europe become a genuine political reality, capable of asserting itself on the international scene."

The visit was marred by an astonishing occurrence. A French bomb-disposal technician planted a small quantity of explosives, without detonator to be sure, on the grounds of the residence of the French Ambassador, where Mitterrand was to hold a reception. The technician, acting without authorization, apparently wanted to test British antibomb squads. The explosives were quickly discovered by dogs trained to detect them. Understandably edgy in the wake of the Irish Republican Army bombing in Brighton two weeks ago aimed at Prime Minister Margaret Thatcher, British authorities questioned the French technician at length and gave him what was described as a "verbal lashing."