188 CIRCULATION. 



can easily be observed ; but the change in length of the heart 

 during its systole has been, and is now, a matter of discussion. 

 All who have studied the heart in action have observed 

 changes in length during contraction and relaxation ; but the 

 contemporaries of Harvey were divided as to the periods in 

 the heart's action which are attended with elongation and 

 shortening. Harvey himself is not absolutely definite on this 

 point. In one passage he says, in describing the systole, 

 " that it is everywhere contracted, but especially towards the 

 sides, so that it looks narrower, relatively longer, more drawn 

 together." 1 In his description of the case of the Viscount 

 Montgomery, who suffered from ectopia cordis, he states that 

 during the systole, the heart " emerged and protruded." a Ye- 

 salius, Riolan, Fontana, and some others, contended for elon- 

 gation during the systole; but Haller, Steno, Lancisi, and 

 Bassuel contended that it shortened. The view generally 

 entertained at the present day is that the heart becomes 

 shorter during its systole; but there are some eminent au- 

 thorities who hold an opposite opinion. Among the latter 

 may be mentioned Drs. Pemiock and Moore, who made a 

 great number of experiments on the action of the heart in 

 sheep and young calves. These experiments were made in 

 Philadelphia in 1839, and it was apparently demonstrated 

 that the heart elongated to such a marked degree, that the 

 distance could be measured with a shoemaker's rule. In one 

 experiment (a ewe one year old), the elongation was a quarter 

 of an inch. 3 Of all the writers of systematic works on phy- 

 siology, Prof. Dalton is the only one, as far as we know, who 

 accepts this view. 4 The experiments of this observer appa- 



1 HARVEY'S Works, published by the Sydenham Society, p. 21. 



2 Ibid., p. 384. 



3 HOPE, on the Heart. American Edition by PENNOCK, Philadelphia, 1846, 

 p. 59. 



4 DALTON, A Treatise on Human Physiology, Philadelphia, 1864, third edition, 

 pp. 275, 276. The heart of the eel is said by Haller to elongate during its 

 ventricular systole, though this is denied by Fontana (Memoires de Haller, Lau- 



