ON DEATH. , 49 



*#. Sulphuretted hydrogen, nitrous gas, effluviae from 

 privies produce it more speedily than other gases, or than 

 a vacuum does. 



Q. How do you divide asphyxise?, 



*#. Into those produced by want of air, and those from 

 poisonous gases. In the first, death is produced by the 

 circulation of black blood purely; in the second there is 

 added to. the black blood a deleterious substance. In some 

 cases death is produced by the poisonous effluvise alone. 



Q. There are two modes by which deleterious gases af- 

 fect the lungs, what are they ? 



*#. They affect the nerves of the lungs, and these react 

 by sympathy on the brain; and they pass into the blood, 

 and thus likewise exert a morbid influence on the brain 

 and organs in general. Simple contact of a deleterious gas 

 with a mucous surface does not produce death immediately. 



Q. Is it certain that air will pass through the membrane 

 lining the bronchiae, into the blood-vessels? 



/?. It is rendered certain by direct and analogical proof. 

 Experiments on animals show that a quantity of air en- 

 ters the blood-vessels, and may be drawn off with the 

 blood. Hydrogen has been drawn from the arteries, almost 

 as pure as when forced into the blood. 



Q. On what system, do the deleterious vapours absorb- 

 ed into the general circulation, in asphyxia, operate ? 



J3. On the brain and nerves. The reasons for this opi- 

 nion are, that the symptoms are stupor and convulsions; 

 that the symptoms are the same when the gases are in- 

 haled, as when injected into the brain; the phenomena, on 

 restoration from this absorption, are cephalic, such as tre- 

 mors, pain in the head, &c. These all point to the brain 

 as the system on which these deleterious poisons operate. 



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