RELATIONS TO RESPIRATION. 291 



fact is evident, that arrest of respiration produces arrest of 

 circulation. This is ordinarily attributed to an impediment 

 to the passage of blood through the lungs, when they no 

 longer contain the proper quantity of oxygen. This view is 

 entirely theoretical, and has been disproved by experiments 

 dating more than half a century ago. In 1T89, Goodwyn 

 advanced the theory that, in asphyxia, the blood passes 

 through the lungs, but is incapable of exciting contractions 

 in the left ventricle. 1 Bichat, in his celebrated essay " Sur 

 la Vie et la Mort" 1805, proved by experiment that black 

 blood passes through the lungs in asphyxia, and is found in 

 the arteries. His theory was that non-aerated blood, circu- 

 lating in the capillaries of the nervous centres, arrests their 

 function, thus acting indirectly upon the circulation; and 

 that finally the heart itself is paralyzed by the circulation of 

 black blood in its substance. 



Dr. John Eeid, in an article " On the Cessation of the 

 Yital Actions in Asphyxia," 2 describes an experiment in which 

 a hemodynamometer applied to the femoral artery of a dog 

 indicated increase in the arterial pressure during the first 

 moments of asphyxia, followed finally by a depression in the 

 mercury. He found a corresponding diminution in the 

 pressure in the vein of the opposite side. " This was so un- 

 looked for at first sight so inexplicable, and so much at 

 variance with my preconceived notions on the subject," says 

 the author, "that I was strongly inclined to believe there 

 must be some source of fallacy ; but after repeating the ex- 

 periment more than twenty times, and invariably with the 

 same results, I was at last compelled to admit its accuracy." 

 This he surmises is due to " an impediment to the passage of 

 the venous blood through the capillaries of the systemic cir- 

 culation." In his conclusions at the end of the article, how- 



' P. BERARD, Cours de Physiologic fait d la Faculte de Medeeine de Paris, 

 1851, tome iii., p. 444. 



2 JOHN REID, M. D., Physiological, Anatomical, and Pathological Researcltes, 

 Edinburgh, 1848, p. 26. (Article extracted from the Edinburgh Medical and 

 Surgical Journal, April, 1841.) 



