STOMACH AND INTESTINE. 



317 



minal muscles be also brought into vigorous 

 action, the whole force of either of these 

 two muscular strata may be regarded as com- 

 pressing the viscera within the abdominal 

 cavity. And since many of these viscera are 

 hollow organs, which enclose moveable con- 

 tents, and communicate with the exterior of 

 the bod}, such a forcible pressure will expel 

 the contents from their interior, so soon as 

 their terminal orifices are thrown open; 

 whether by their relaxing spontaneously, or 

 yielding to any superior force. In this way, 

 the contraction of the walls of the belly plays 

 an important part in the acts of defaecation, 

 micturition, and parturition, as well as in that 

 of vomiting. 



Now in the three former of these acts, the 

 intermittent abdominal pressure does but assist 

 those more continuous expulsive contractions 

 which are effected by the muscular walls of the 

 hollow viscera themselves. And supposing 

 that the cardia were open, and the pylorus 

 shut, it is obvious that either pressure on the 

 stomach, or contraction of its walls, would 

 alike tend to expel its contents. 



Careful observation of the act of vomiting 

 in any of the higher animals will show that it 

 is always assisted by the abdominal pressure. 

 And the vivisections which many experi- 

 menters have practised, agree in carrying this 

 investigation further ; and in stating, that 

 this pressure, which ordinarily results from 

 simultaneous contractions of the diaphragm 

 and abdominal muscles, may be due solely to 

 the latter*, (as is normally the case in 

 Birds f ), or to the former, or even to an 

 inconsiderable compression exerted by the 

 lower ribs upon the epigastric region.^ 

 While the solitary observation of Maingault <J, 

 which affirms the occurrence of vomiting in 

 the absence of all such pressure, stands ex- 

 pressly contradicted by the Committee of 

 the French Academy appointed to report 

 upon his Memoir. 



But whether the stomach really contracts 

 during the act of vomiting, and if so, what 

 is the amount of assistance which it thus af- 

 fords this process, are questions which, long 

 the object of physiological controversy, can 

 even now scarcely be regarded as decided. 



On the one hand, there are not wanting 

 experiments, which show that the act of 

 vomiting may be effected without the aid of 

 any gastric contractions whatever. Among 

 such we may specially adduce the vivisection 

 practised by Magendie ||, in which a Pig's 

 bladder was substituted for the stomach of 

 a living Dog, and was subsequently emptied, 

 bv vomiting, of a large part of its contents. 

 Such a result conclusively proves that gas- 

 tric contractions are not essential to the 

 physical act of vomiting, however frequently 

 they may take a part in the process. And 



* Magendie, Sur le Vomissement, pp. 22. 37, 38. 

 f Krimer in Horn and Xasse's Archiv. 1816. 

 J Bulletin de la Facultede Medecine, 1813. No. 10. 

 p. 481. et seq. 



Sur le Vomissement Paris, 1813. 

 II Op. cit. p. 18. 



that inactivity of the stomach, which has 

 been directly observed by many * physio- 

 logists in the artificial vomiting of vivisected 

 animals, has been all but actually seen in the 

 living human -j- subject. 



On the other hand, the observations in 

 which a muscular contraction of the stomach 

 has been seen to concur in this act, are even 

 more numerous than the preceding. The 

 amount of such contraction seen appears to 

 have varied, having sometimes been so slight 

 as to be scarcely visible. In all instances, it 

 has specially engaged the pyloric extremity of 

 the organ: and, in most, it is described as 

 either circular J, and alternating with relaxa- 

 tion; or peristaltic, like that found in the di- 

 gesting stomach, independently of all vomiting. 

 And though an anti-peristaltic movement is 

 detailed by Haller and others, yet so far as I 

 can find, this doctrine, which is expressly con- 

 tradicted by the observations just referred to, 

 rests only on one or two vague descriptions 

 of Wepfer, Rudbeck, and Schwartz. 



From these very brief allusions to both 

 sides of this conflicted question, the author 

 has been careful to eliminate every statement 

 which does not refer to actual facts. And 

 the reader must recollect, that not only 

 does the stomach offer few obstacles to such 

 direct observations |j, but that some of those 

 summed up in the above statements, are ren- 

 dered additionally trustworthy by being results 

 quite at variance with the theories of their 

 observers ; while others have been confirmed 

 by very frequent and careful repetition.^ 



Hence, on the whole, I think we must con- 

 clude as follows: The act of vomiting is es- 

 sentially, and perhaps sometimes solely, the 

 result of powerful abdominal pressure on the 

 contents of the stomach. It implies a pa- 

 tulous cardia. The abdominal pressure which 

 effects it, often coincides with, and is aided 



* Bayle, Wepfer, Chirac, Baciaccus, Senac, 

 Schwartz, and (especially) Magendie. 



t Lepine, Bulletin de* r Academic de Medecine, 

 vol. ix. p. 146. In this case, which has been strangely 

 misquoted by many English authors, the stomach 

 was protruded from a wound in the belly. It con- 

 tained food and air, remained quite motionless, and 

 could not even be excited to contract by manual 

 titillation and pressure. But as soon as "it was re- 

 turned into the cavity of the belly, the abdominal 

 efforts at vomiting, which had been previously 

 ineffectual, discharged its contents. 



I Haller, Opera Minora, vol. i. p. 389. ; Schwartz, 

 in Haller's Disp. Anat. vol. i. p. 327. ; Wepfer, Sur 

 la Cigue aquatique, p. 253. ; the Author, Op. cit. 

 p. 11.; Betz, Wurtemberger Corr. Blatt. Bd. xx. 

 pp. 145. et seq. 



Rudbeck, quoted by Morgenbesser in Haller's 

 Disputationes Anatomicae, vol. i. p. 293. ; Wepfer, 

 Op. cit. 251. and elsewhere; Schwartz, loc. cit. Rud- 

 beck describes it as a contraction, which began at 

 the pylorus, and was followed by a systole of the whole 

 organ, from the lower to the upper orifice. While, 

 according to Wepfer, it commenced in the duodenum, 

 and passed hence towards the pylorus and the mid- 

 dle of the stomach. 



See remarks on the gastric movements, p. 312. 

 Although unable to quote exactly, I believe 

 Magendie somewhere alludes to his own results as 

 confirmed by the vivisection of about two hundred 

 animals. 



