70 Borelli and the Influence [lect. 



" or some sort of clothing, the purpose of lessening the effects 

 "of heat in summer and of cold in winter. On the contrary, 

 "I am persuaded that the flesh of muscles which is different 

 "from everything else in the whole body, is the chief agent, 

 "by aid of which (the nerves, the messengers of the animal 

 " spirits not being wanting) the muscle becomes thicker, shortens 

 " and gathers itself together, and so draws to itself and moves 

 "the part to which it is attached, and by help of which it again 

 "relaxes and extends, and so lets go again the part which it 

 " had so drawn. It is clear that the proper substance of an 

 " organ is the agent of the primary functions of the organ, as 

 "is the case in the brain, heart, liver, lungs, spleen, kidney and 

 "testes." 



Fabricius discourses in three long rambling chapters on 

 the structure, the action, and the uses of muscle. In these he 

 shews here and there the influence of new ideas, as for instance 

 when he compares the action of a nerve in inducing muscular 

 contraction, though itself not contracting, to that of a magnet 

 which causes a piece of iron to move, though not itself moving. 

 Yet his teaching is on the whole the old teaching that the 

 contractile power resides in the fibres of the muscle, not in the 

 flesh. So far from advancing beyond Vesalius, he falls behind 

 him; in this as in other matters Galen is his master, not Vesalius. 

 Indeed when Borelli attacked the problem, this was very much 

 where Vesalius had left it, for Descartes had passed it lightly 

 over. 



He had the advantage of being able to start with a truer 

 knowledge of the minute structure of muscle. As we shall see 

 in the succeeding lecture the microscope had about this time 

 come to the aid of the anatomist, and Malpighi, Borelii's friend 

 and colleague at Pisa, was using the new aid as a means of 

 achieving brilliant discoveries concerning the finer structure of 

 living beings. Nor was the new instrument being used by 

 anatomists at Pisa only. Before Borelii's book was published, 

 but, probably, not before he had written or at least begun 

 to write it, there appeared in 1664 a little tract, De musculis 

 observationum specimen, expanded, and illustrated with figures 

 a few years later in 1667 as Elementorum myologiae specimen, 



