Proceedings of the British Association, 145 



Mr. Elias Hall read a communication ' On the Midland Coalfield/ 

 being the substance of a pamphlet in course of publication. 



Thursday. 

 Section E.— MEDICAL SCIENCE. 

 The first paper read was a report on Asphyxia, by Mr. Erichsen, 

 The different theories previously held on the subject were examined, 

 and tested by a series of experiments, and from an examination of 

 all the results the following conclusions were drawn : — 1st, That, 

 although the persistence of the respiratory movements has some 

 influence in maintaining the circulation through the lungs, yet that 

 their arrest is not by any means the sole cause of the cessation of 

 the circulation. — 2nd, That a diminution in the force and frequency 

 of the contractions of the heart, consequent upon the altered quality 

 of the blood circulating through its muscular substance, is one of 

 the principal causes of the cessation of the circulation in asphyxia, 

 as is evident from the fact that when the force of the heart's contrac- 

 tions is maintained by a supply of arterial blood to its muscular 

 substance, it is enabled to propel black blood through a collapsed 

 lung. — 3rd, That the obstruction which has been found to take place 

 in the pulmonary and systematic circulation is due to the venous 

 blood exciting the contractility of the minute divisions of the arteries 

 and pulmonary veins by acting on their special sensibility. — 4th, That 

 the cause of the stoppage of the circulation in asphyxia is, therefore, 

 threefold, depending, 1st, upon the arrest of the respiratory move- 

 ments ; 2nd, upon the weakening of the heart's action, and 3rd, upon 

 the obstruction afforded to the blood by the refusal of the smaller 

 divisions of the arterial system to receive venous blood. The author 

 then adverted to the subject of the treatment of asphyxia. After re- 

 viewing the plans generally adopted, he stated as a fact, determined by 

 a considerable number of experiments, that if artificial respiration be 

 set up, even after the heart have entirely ceased to act, the left cavities 

 of that organ will fill themselves with arterial blood, the congested 

 condition of the lungs be removed, and the pulmonary artery be 

 emptied of its blood, and this without the action of the heart being 

 renewed ; unless when pure oxygen gas was used, when these effects 

 took place with much greater rapidity ; and the author succeeded in 

 many instances in restoring the circulation after the contractions ot 



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