Two days after the alleged chemical attack on the Damascus suburbs of Eastern Ghouta, chemical-weapons experts are dissecting amateur footage to determine exactly what might have caused the deaths of so many hundreds of Syrians. All agree this time, unlike in past alleged attacks, that the number of victims and the lack of marks from physical wounds on their bodies point to some form of chemical poisoning. But they are puzzled that the symptoms\u201d\u201dinsofar as they are visible from the videos\u201d\u201ddo not exactly correspond to any particular known substance, including the large quantities of mustard gas, sarin and VX which President Bashar Assad is thought to have at his disposal. \u201cIt is beyond doubt that something has made a lot of people ill and killed them,\u201d\u009d says Dan Kaszeta, a chemical and biological expert who now runs Strongpoint Security, a defence consultancy. \u201cBut there is no obvious agent.\u201d\u009d<\/p>\n