approachable, but not with total safety; in this photo, the person descending from the rim of the cone is doing so in haste, fleeing the rain of ash and hot rocks from an unexpectly strong "chuff". In addition to the possibility of being hit by a falling bomb during explosive eruptions, visitors to the rim must also be cautious about volcanic gases. Here yellow sulfur sublimates on the rim trail attest to the sulfurous gases pouring over the crater rim. When inhaled, sulfur dioxide combines with water in the lungs to form sulfuric acid. The burning sensation is very unpleasant, and high doses could be harmful. Becoming trapped in a cloud of sulfurous gases could be fatal. It is best to stay on the up-wind side of the vent, where you can drop down below the rim when blasts of sulfurous gases swirl your way. Also, keep an eye out for a quick retreat route if the wind direction shifts and more than just a momentary swirl of noxious gases heads your way. By June 1989 the previous year's summit cone had collapsed, and a double crater in the shape of a figure-8 had taken its place. The white clouds are steam, but near the right edge of the photo a bluish cloud can be seen, which is sulfurous and to be avoided. Within the nearer of the twin craters rose a bizarre chimney of congealed lava . This double crater still existed in March 1990, but the near crater