NEWS AND VIEWS VOLCANOLOGY------mild outbursts from Galeras in Colombia, Explodingvolcanic myths Unzen in Japan and Guagua Pichincha in Ecuador have taken the lives of eleven Jonathan Fink volcanologists. Re-examination of seismic and gas data from the days before the FOR students of explosive volcanism, the billions of dollars' worth of military equip­ Galeras eruption revealed correlations 1990s have been a time of unparalleled ment. Last September's reawakening of that are now being used to look for future 3 accomplishment tempered by tragic loss. Rabaul Caldera in Papua New Guinea explosions of this type . The Unzen lava New modelling experiments from two prompted an evacuation that greatly re­ dome, whose collapse gave rise to deadly groups of workers may now help us to duced casualties. In both cases, scientists pyroclastic surges, had been carefully come up with better ideas of when volca­ were able to notice familiar patterns of monitored for months. At Pichincha the noes are due to erupt violently, lessening deformation and seismicity and then ex­ two scientists killed had received a warn­ their deadly impact. Mader et a/.J pub­ plain the significance of this activity to ing based on seismicity an hour before. lished their results late last year; those of responsible civil officials. This recognition Thus the deaths arose not so much from Sugioka and Bursik2 appear on page 689 came from studying what had occurred at lack of information as from the inability to of this issue. eruptions elsewhere, and also from pre­ interpret it correctly. An important lesson Geologists have had two notable suc­ dictions of what might happen locally that has been learned from these fatalities cesses in their recent attempts to mitigate based on theoretical models. is that better theoretical models are the hazards of erupting volcanoes. The Over this same period, smaller explo­ needed to tell us which data to collect and most dramatic was in 1991 at Mount sive eruptions have been more difficult to what such numbers mean. Pinatubo in the Philippines, where timely anticipate, and both scientists and civ­ Most geologists agree that the trigger­ warnings saved thousands of lives and ilians have paid the price. Comparatively ing of explosive eruptions involves certain OBITUARY-- -, AdolfButenandt (1903-1995)

ADOLF Butenandt, the outstanding bio• tants of Drosophila and the flour moth For his next project, Butenandt chose chemist in Germany in the first half of Ephestia were known that had light eyes another problem in insect biochemistry: this century, died in Munich on January because one component of the eye isolation of the hormone responsible for 18. Given the methods of the time, his pigments was missing. Transplantation moulting. I was a participant in this achievements in isolating hormones experiments had shown that a soluble research. The bioassay concerned was were truly towering. substance was responsible for pigment based on work by G. Fraenkel, and in• Butenandt studied chemistry and biol• volved use of ligated larvae ofthe blowfly ogy in Marburg and Gottingen, and did Calliphora. The starting material con• his PhD thesis under the supervision of sisted of pupae of the silkworm, and in Adolf Windaus. As a young PhD, he was the summer of 1953 we bought up all silk appointed at the Institute of Organic cocoons available. We used cocoons of Chemistry in Gottingen, under Windaus, both sexes, the males for the moulting to start work on the female sex hormone, hormone, the females for the sex attrac• now known as oestrone. He isolated this tant. From 500 kg of pupae, we ended up hormone in the summer of 1929, simul• with 25 mg of the crystalline hormone taneously with but independent of Ed• which we called ecdysone. The structure, ward Doisy, and by 1932 had already when elucidated, came as a surprise. worked out its chemical structure. He Ecdysone was another steroid hormone. then turned to the male sex hormone The silkworm's sex attractant is pro• androsterone, which he isolated from duced in small glands sitting at the tip of men's urine. Time-consuming purifica• the female's abodmen, and is released to tion procedures, guided by a bioassay, lure the male moths for copulation. Iso• were necessary to obtain crystals of the lating it was again a fight for enough hormone. The structure followed shortly starting material. The great campaign of afterwartjs: androsterone also turned out 1953 yielded 200,000 sex glands, but to be a steroid. Butenandt (standing) at work with Ulrich even that was not enough. Butenandt and The next task was progesterone; this Westphal on the isolation of progesterone his co-worker Hecker had to order time the starting material was pig's in 1934. 500,000 glands from Japan, and from ovaries. Again, difficult purification pro• this material the attractant was extracted cedures monitored by a biossay were formation. Butenandt followed up a hint and its structure determined. This was necessary. In the final step, a chemical that this substance might be a metabolite the first insect pheromone to be isolated. reaction (formation of a semicarbazone) of tryptophan. He went on to discover that In 1959, Adolf Butenandt was elected helped to achieve crystallization. The it was kynurenine, which led him to President of the Max-Planck-Gesellschaft results were published in 1934. So, within postulate that "genes act by providing an der Wissenschaften (this was the new a mere five years Butenandt had isolated enzyme system that converts tryptophan name for the former Kaiser-Wilhelm• three important hormones. For this work to kynurenine". This was nothing other Gesellschaft). He served in this position he received the Nobel Prize for Chem• than the one-gene - one-enzyme hypoth• until his retirement in 1972. istry in 1939, but the Nazi government esis, published in 1940. Peter Karlson prevented him from accepting the By this time, Butenandt had already honour. risen to the position of director of the Peter Karlson is a Professor Emeritus at Butenandt then left the field of steroid Kaiser Wilhelm Institute in Berlin• the Philipps-Universitat Marburg, Emil• hormones and began to work on the Dahlem. In 1944, the institute was trans• Mannkopff-Strasse 2, 0-35037 Marburg, genesis of insect eye pigments. Mu- ferred to Tiibingen because of the war. Germany.

660 NATURE· VOL 373 . 23 FEBRUARY 1995