Now, knowing the case of Mr. Clive, the Englishman, and his guide, Wylie, who were overwhelmed by hydrogen sulfide while photographing Boiling Lake on December 10, 1901, it looks to me as though the rotten-egg smell may play a large part in the killings at Death Gulch, as well as in some poison tragedies of Java. Boiling Lake is at the south end of Dominica Island north of Martinique. There are four solfataras and the scalding lake, the latter near the interior village of Laudat, at the head of a volcanic valley, and four miles on horseback from Roseau, a shore town southwest. When Mr. Clive, Wylie, and Matson--another native guide--looked down at the hot pool, Matson noticed it boiling without vapor, and called attention to the danger. However, they went on to the lake. Matson later reported, “I inhaled something offensive and felt as if I was dying. I ran, and lost consciousness. I came to in a ravine and found Wylie lying where I had left him.” Clive, refusing to leave Wylie, sent Matson for help, but when rescue parties arrived, both men were dead. At Boiling Lake there was no eruption, no vapor, only the very bad smell. All the symptoms indicated a sudden change in the pool from steam to excessive hydrogen sulfide. And five months later, at Pelée across the channel from Dominica, excessive hydrogen sulfide set off the great explosions. In view of these phenomena it seems likely that Death Gulch in the Yellowstone also kills with sulfur gas, the odor of which is so strong there. Day and Allen associate hydrogen sulfide with the limited Yellowstone sulfate areas, of small water discharged, and such is Death Gulch. One part hydrogen sulfide in 200 parts of air is fatal to mammals, and it may come up in gushes. Carbonic acid asphyxiates, but it is not a poison and when it is free is so heavy as to mix with air very little. Death Gulch is not a place of lime deposition like Mammoth Hot Springs, where carbonated water decomposes underlying limestone. Europe was to be the next step in my education. As assistant in petrography and graduate student at Harvard, I was encouraged by Wolff to plan for Heidelberg. There I was to find H. Rosenbusch, who had put system into the infinite series of minerals in rocks. But my journey to Heidelberg began with a geography congress in London and a geology congress in Zurich. These meetings were with such bigwigs as Lord Curzon, Henry M. Stanley, and famous arctic explorers, and I was surprised to find that all these VIP’s looked like ordinary men. Unfortunately for me, this realization came a little late.