Andrea Musacchio

refinements of this equipment. There was a direct analogy with the voltage clamp approach in nerve, but now length or force became the controlled parameter in place of voltage. This approach was applied in a quantitative study of the relation between the steady force produced by an active muscle fiber and its length: Huxley showed that force is proportional to overlap between the thick and thin filaments as predicted by the theory; moreover, maximum velocity is independent of overlap, indicating that it springs from some intrinsic kinetic mechanism of the cross-bridges. Most of Huxley’s later work was concerned with the rapid mechanical transients that are elicited when an active muscle fiber is subjected to a rapid length change. As with the squid giant axon, there are puzzling kinetics to account for, and Huxley showed that the observed dependence of initial recovery rate on size of length change can be explained by a two-state force-generating process in the cross-bridges. This theory still awaits final confirmation or disproof, but it has been at the heart of the ‘standard model’ for three decades. On his retirement from the Royal Society Research Professorship that he had held for the last 14 years at UCL, he returned to Cambridge, where he succeeded Hodgkin as Master of Trinity College. He kept a laboratory in Cambridge and contributed a great deal technically to the research of collaborators in the muscle mechanics field, and continued to be very active in the field. His performance at muscle workshops was legendary, when on the final morning he would sum up the whole conference, apparently completely au fait with the work of everyone present, and ready to debate their work with them. There must be hundreds of scientist who benefited from his personal help. Robert Stämpfli has an anecdote about this from Cambridge days: “Huxley was usually hungry at this time of the day and stopped in the midst of an experiment when tea time came. We went to the common room, where a big kettle of water was boiling and tea was available. Several paintings on the wall, particularly the one of Sir Joseph Barcroft, gave a college atmosphere. Huxley, then about 30 years old, was known to come in regularly for tea and to eat ‘buns’ with margarine and jam. All those in the laboratory and others from outside, who wanted to make use of his remarkable intelligence, came and waited respectfully until his second helping before asking questions. He would at first listen and continue chewing. Then, instead of answering directly, he usually reformulated the question much more precisely and to the point than others had been able to put it. He then gave a quick answer if the problem had become a pseudoproblem by his new formulation. But quite often he took a pencil and a sheet of paper and began to develop the adequate mathematical expression. The general belief of the audience was that no one could ever find a mistake in the work of his brain. This explained why so many who had difficulties getting their problems straight used Huxley as a human computer.” Many honours came his way, notably a knighthood in 1974 and the Order of Merit in 1983. There were a number of public appointments, among which he was President of the Royal Society in 1980–85. He married Richenda Pease in 1947, and they had six children. He and Richenda (who predeceased him in 2003) were wonderfully complementary, with her spontaneity and warmth balancing his critical and sometimes formal manner, though in private he showed an unexpectedly sympathetic side to his character and a surprisingly broad sense of humor. The two were extremely hospitable and seemed to run a continuous open house for foreign scientists whether at Trinity or at their home in Grantchester. Andrew Huxley will be most fondly remembered as a ‘scientist’s scientist’, who by an extraordinary combination of sheer mental ability, intuition and application could do easily and elegantly everything that lesser mortals found difficult or impossible: he seemed to have an extra gear which, when engaged, propelled him rapidly out of intellectual sight.