Lawrence Sheriff St, Rugby CV22 5EH, United Kingdom
From the Reverend T, Oldham’s preparatory school at Blackheath, Lucas went to Rugby School on a classical scholarship in 1893.
College/University
Gallery of Keith Lucas
Cambridge CB2 1TQ, United Kingdom
Lucas matriculated in Trinity College, Cambridge, on a minor classical scholarship in 1898. In addition to the Bachelor of Arts degree in 1901, he received the Master of Arts in 1905 and the Doctor of Science in 1911.
Lucas matriculated in Trinity College, Cambridge, on a minor classical scholarship in 1898. In addition to the Bachelor of Arts degree in 1901, he received the Master of Arts in 1905 and the Doctor of Science in 1911.
Keith Lucas was a British physiologist. He worked at Trinity College, Cambridge doing pioneering work in Neuroscience.
Background
Lucas was born on March 8, 1879, in Greenwich, England, the second son of Francis Robert Lucas, an inventor, and engineer who supervised the laying of the early intercontinental submarine telegraph cables and who ultimately became managing director of the Telegraph Construction and Maintenance Company. Under his father’s influence, Lucas early displayed great mechanical ingenuity, remarkable manual dexterity, and a deep interest in science and engineering. His mother was the former Katherine Mary Riddle, granddaughter of Edward Riddle and daughter of John Riddle, successive directors of a school for sons of naval officers in Greenwich and both renowned as teachers of navigation and nautical astronomy.
Education
From the Reverend T, Oldham’s preparatory school at Blackheath, Lucas went to Rugby School on a classical scholarship in 1893 and then on a minor classical scholarship to Trinity College, Cambridge, where he matriculated in 1898. Lucas had already decided to study science; and he began at once to read for the natural sciences tripos, in part I of which he took the first class in 1901. In keeping with his interests, and despite two full years of support on a classical scholarship, Lucas had as his director of studies at Trinity the noted physiologist Walter Morley Fletcher. In 1901, under the strain of his studies and the death of an old school friend in the Boer War, Lucas suffered a breakdown in his health and left Cambridge for two years. Part of this period he spent in New Zealand, where he carried out a bathymetric survey of a number of lakes.
By the time he returned to Cambridge in the autumn of 1903, Lucas had decided to devote himself to a career in physiological research. He had in fact already devised, at home and on his own, an impressive photographic recording method for tracing the events of muscle contraction. So clearly had he formulated his research interests that he was allowed to forgo the usual routine of organized course work and examinations for part II of the natural sciences tripos and was immediately given a place in the crowded physiological laboratory at Cambridge, initially in a sort of anteroom passageway and later in a small cellar. In addition to the Bachelor of Arts degree in 1901, Lucas received the Master of Arts from Cambridge in 1905 and the Doctor of Science in 1911.
In 1904 Lucas won the Gedge Prize and the Walsingham Medal and was elected fellow of Trinity College. He was appointed an additional university demonstrator in physiology in 1907 and lecturer in natural science at Trinity College in 1908. He was elected fellow of the Royal Society in 1913, having been Croonian lecturer the year before. From 1906 to 1914 Lucas was a director of the Cambridge Scientific Instrument Company. A member of the Trinity College Council, he also helped to plan the new physiological laboratory built at Cambridge in 1914.
Upon the outbreak of World War I, Lucas enlisted and in September 1914 was assigned to the experimental research department of the Royal Aircraft Factory at Farnborough. There he applied his graphical recording methods to an analysis of roll, pitch, and yaw in airplanes. He also helped to design an accurate bombsight and a new magnetic compass which greatly improved aerial navigation and which was granted a War Office secret patent in July 1915. His contributions in this area were recognized in the published report of the Advisory Committee for Aeronautics. In September 1916, after repeated requests, he was allowed to attend the Central Flying School, where he quickly qualified as a pilot. He was killed, while flying solo, in a mid-air collision. After his death, his wife and sons changed their names by deed poll to "Keith-Lucas."
Lucas’ career in physiological research was devoted wholly to investigating the properties of nerve and muscle, especially the characteristics in each of waves of excitation (what Lucas called "propagated disturbances"). The dominant and most valuable features of his work, in general, were clarity, precision, and enormous methodological originality. He designed an instrument for the analysis of photographic curves from the capillary electrometer, a method of drawing fine glass tubes of uniform dimensions for the capillary electrometer, and a photographic time marker along the lines of Eint-hoven’s string galvanometer.
Achievements
Views
Lucas produced a series of valuable experimental results and established at least one fundamental principle: the "all or none" law for ordinary skeletal muscle. Since the work of Henry P. Bowditch in 1871, it had been known that cardiac muscle follows an "all or none" rule: a given stimulus either evokes the maximum possible contraction, or it evokes no contraction at all; if a cardiac contraction does occur, its strength is independent of the exciting stimulus. Some indirect evidence existed that this principle applied as well to skeletal muscle, as Francis Gotch had explicitly suggested in 1902; but direct support for the suggestion was lacking. This support was provided by Lucas in two papers published in 1905 and 1909.
In the first paper, Lucas showed that when the frog’s cutaneus dorsi muscle is stimulated directly by electrical currents, the resulting contraction increases in discrete, discontinuous steps as the stimulus is increased. Whether the preparation is the cutaneus dorsi muscle as a whole (consisting of 150 to 200 individual muscle fibers) or only a small section of the muscle, these discrete steps are always fewer than the number of individual muscle fibers in the preparation. This result suggested that the individual muscle fibers fall into distinct groups according to their excitability and that each discrete step of increased contraction marks the excitation of an additional fiber or small group of fibers of similar excitability.
In the paper of 1909, Lucas confirmed these earlier results under more normal conditions, for he now evoked contraction not by direct stimulation of the cutaneus dorsi muscle but through stimulation of its motor nerve fibers. Persuasive evidence was thus produced that for each skeletal muscle fiber, as for cardiac muscle, contraction (if evoked at all) is maximal regardless of the strength of the exciting stimulus. A stronger stimulus increases contraction in an ordinary many-fibered muscle only because it activates a larger number of the individual constituent fibers; and the "submaximal" contraction of such a muscle is merely the maximal contraction of less than all of its fibers. The absence of submaximal contractions in the heart is not to be ascribed to any fundamental differences in the functional capacities of skeletal and cardiac muscle cells but, rather, to the fact that cardiac muscle is functionally continuous, its fibers being in connection with one another, while skeletal muscle fibers are separated by their sarcolemma. By 1914 the "all or none" law had been extended to motor nerve fibers by Lucas’ most celebrated student, Edgar Douglas Adrian, later a Nobel laureate in physiology or medicine.
In addition to the "all or none" law and the Lucas-Adrian theory of summation, Lucas contributed to the physicochemical theory of excitation, although his role in this area was more that of an effective and suggestive critic than of a creative pioneer. His departure point here was Walther Hermann Nernst’s influential theory of the local excitatory process, according to which the threshold of excitation is reached when a certain difference of ionic concentration is produced at a semipermeable membrane contained in the excitable tissue. Drawing in part on the work of A. V. Hill, another young Cambridge physiologist and future Nobel laureate, Lucas argued that Nernst’s theory, properly conceived and appropriately modified, could account for virtually all the phenomena of local excitation. In his Croonian lecture of 1912, Lucas emphasized in typical fashion that what difficulties the theory did present "seem to dovetail into one another, being probably expressions of the common property of the tissues."
Membership
Royal Society of London
,
United Kingdom
1913
Connections
Lucas married Alys Hubbard in 1909. She was the eldest daughter of the Reverend C. E. Hubbard. They had three sons, Professors Alan Keith-Lucas, David Keith-Lucas, and Bryan Keith-Lucas. After his death, his wife and sons changed their names by deed poll to "Keith-Lucas."