On Muscular Irritability after Systemic Death. 339 



May 29, 1873. 



Sir GEORGE BIDDELL AIRY, K.C.B., President, in the Chair. 



The Croonian Lecture, u On Muscular Irritability after Systemic 

 Death/'' was delivered by Benjamin Ward Richardson, 

 M.D., E.R.S. 



(Abstract.) 



The Lecturer commenced by referring to the labours o£ Dr. Croone, 

 the Physician with whose name this lecture is connected. Croone was 

 distinguished as one of the founders and as first Registrar of the 

 Royal Society, and his scientific work included important contributions 

 to the subject of muscular motion. Immediately preceding Croone, 

 Nicholas Stenon, of Copenhagen (first an anatomist and afterwards 

 Bishop of Heliopolis, a man whom Haller has described as vir industrius, 

 candidus, innocuus et magnus inventor, and whom the Grand Luke of 

 Tuscany buried in the tomb of his Royal house), had made known the fact 

 that the contractile portion of muscle is resident in the carneous or fleshy 

 part of the muscle, as distinguished from the fibrous part. This discovery, 

 seized by Croone, led him to observe that the fleshy part of muscle is 

 made up of fibres, and that each fibre possesses a distinct power of 

 contraction ; so that, to use his own words, " the force of the whole 

 muscle is but an aggregation of each particular fibre." 



Upon this observation, perfectly original at the time it was announced, 

 Croone advanced an hypothesis as to the cause of muscular motion. 

 He showed that for muscular contraction it was necessary that the 

 arteries should supply blood to the fleshy muscular fibres — that the 

 blood should pervade the fibres — that in its course, forced on by the 

 stroke of the heart, it should mix with another liquor within the muscles, 

 and diffuse into the minute vesicles of which each muscular fibre is 

 ultimately composed. To complete the mechanism for motion, he held 

 that the nervous filaments which ramify into each muscle supply a 

 refined fluid, much more active than the muscular fluid, by which the 

 activity of the muscle is called into play. 



The lecturer next briefly traced the various hypotheses that have been 

 advanced to explain muscular motion since the time when Croone made 

 his original observations, the purport of the argument being that, 

 although great advances have been made in the study of structure, and 

 one very great advance in the study of function, viz. by Haller in his 

 separation of the respective forces of nerve and muscle, the precise question 

 of the cause of muscular motion remains much in the same doubt as 

 Croone left it. 



Respecting the various theories and hypotheses since the time of 



