ASPHYXIA. 



1. The first opinion on this subject, which blood can bo arterialized,) but to the penetra- 



need be noticed here, is that which was sup- tion of the muscular substance of the heart by 



ported by the great Haller, viz. that the circu- venous blood, sent to it by the coronary arte- 



lation, and with it all other functions of the ries, and which he held to be equally (although 



body are brought to a stand, because when the less rapidly) fatal to the vital action of this 



movements of respiration cease, and the lungs organ, as of the brain or nerves, 



are no longer dilated and contracted, there is a 4. Later experiments and observations have, 



mechanical difficulty to the propulsion of the however, shewn that this explanation likewise 



blood through the pulmonary capillaries, by is, in some measure, incorrect. In fact, while 



which the fatal stagnation in these vessels, ob- the free flow of venous blood in the carotid 



vious on dissection, is produced. arteries of an asphyxiated animal was urged 



This doctrine was satisfactorily refuted by with perfect fairness by Bichat, as a refutation 



Goodwyn, in his treatise on the Connection of of the theory of Goodwyn, it was with equal 



Life with Respiration, who shewed that the justice argued by Goodwyn,* in opposition to 



air-cells of the lungs are not necessarily con- Bichat, that if the heart's actions ceased in 



tracted at the time of asphyxia, and that after asphyxia, only because its substance is pene- 



having once admitted air, these cells never are trated by venous blood from the coronary arte- 



so much emptied of it again, or contracted on ries, these actions could not be restored by 



themselves, as to offer any considerable impe- blowing air into the lungs and arterializing the 



diment to the free motion of blood in their blood there. 



parietes. Besides, we know that the same Bichat, indeed, foreseeing this objection, 



stagnation in the lungs takes place in the casp maintained that the artificial respiration never 



of an animal confined in a gas which does not is successful in restoring the circulation, unless 



contain free oxygen, as in the case of drowning employed in the interval which, as was already 



or strangulation, although in the former case, stated, always exists between the occurrence of 



any impediment to the mechanical acts of re- insensibility and the final cessation of the circu- 



spiration that can occur, must be the conse- lation. But subsequent and careful observa- 



quence, not the cause, of the fatal changes tions (e.g. those of lloesler, Edinburgh Journal, 



within the chest.* vol. xxiii) show that life has been restored, by 



2. The well-known theory of Goodwyn him- this means, after warm-blooded animals have 

 self on this subject was, that the venous blood lain from twelve to seventeen minutes after 

 is not an adequate stimulus to the left side of their immersion in water, i. e. until a time when 

 the heart, which in the natural state circulates all observations made by laying open the chests 

 arterial blood only, and which fails to contract of similar animals show that their circulation 

 upon or propel blood which has passed un- must have ceased. The records both of the 

 changed through the lungs.f Humane Society in London and of a similar 



This doctrine was, in its turn, refuted by institution in Paris, seem sufficiently to show 

 Bichat, who showed by experiment that in the that resuscitation has occasionally taken place 

 case of strangulation the venous blood does in the human body after fifteen minutes' im- 

 penetrate the lungs and left side of the heart, mersion.f And we are therefore well assured 

 and is delivered from the carotid arteries if that the arterial ization of the blood at the lungs 

 these are punctured ; that the appearance of may, in some instances, restore the natural state 

 venous blood in these arteries is contemporane- of the heart's action after the circulation has 

 ous with what was described as the second come to a stand. 



stage of asphyxia, viz. the insensibility and Farther, although there is a laboured attempt, 



spasms; and further, his experiments have by Bichat,J to explain the accumulation of 



been generally admitted as affording satisfac- blood on the right side of the heart, and the 



tory evidence, that the circulation of venous comparative emptiness of the left side, in as- 



blood through the brain is a sufficient cause for phyxia, consistently with his own explanation 



these symptoms, and produces them when the of the failure of the circulation ; yet it seems 



venous blood from the heart of one dog is sent obvious, that if that explanation were correct, 



to the brain of another. J He also found by the left side of the heart, receiving the venous 



experiment, that venous blood could be in- blood and contracting on it until it loses its 



jected artificially into the left cavities of the power from the penetration of its own fibres, 



heart, with the effect of exciting, not suppress- should be found after death distended with that 



ing their action . blood; and that the accumulation of blood 



3. Bichat ascribed the cessation of the circu- taking place in the lungs and right side of the 

 lation in asphyxia, however, not to the penetra- heart, indicates that the capillaries of the lungs 

 tion of the brain by venous blood, and the are the main seat of the cause which ultimately 

 consequent insensibility (which is now well stops the circulation. 



known to be compatible with the maintenance That this is really the fact has been more 



of circulation for many hours, provided the unequivocally shown, first, by the experiments 



by Dr. Williams, and afterwards by those of 



1 This point has been further elucidated by some 



experiments, of which an account was read, by * In a paper, not published till after his death, 



the author of this article, to the Medical Sections but contained in the Edin. Med. and Surg. Journal, 



of the British Association. July 1830. 



t Connexion of Life with Respiration, p. 82. t See Cyclopaedia of Practical Medicine, art. 



J Recherches Physiologiques, &c. Art. vii. Asphyxia. 



Recherches, &c. p. 327. j Recherches, &c. art. 6. 



