870 EFFECTS OF MEPHITIC GASES. 



supplied with animal heat, and its arterial pro- 

 perties restored, there is a general reduction of 

 temperature, and a vitiated condition of the blood, 

 attended with universal debility. 



Accordingly, the respiration of impure air is 

 attended first with confusion of the brain, im- 

 paired vision, ringing in the ears, pain in the 

 head, vertigo, stupor, syncope, and general loss 

 of sensibility, or delirium. And as the contractile 

 power of the muscles remains for some time after 

 the voluntary influence of the brain over them is 

 suspended, they contract spasmodically, for the 

 same reason that convulsions are caused by loss 

 of blood, or breathing a rarefied atmosphere. 

 The stomach being no longer supplied with 

 arterial blood, loses the power of digestion, and 

 is affected with nausea or spasms, as in cholera. 

 The pains in the head, back, and limbs, arise 

 from a deficiency of vital heat and arterial blood 

 in those parts, and are not essentially different 

 from the aching sensation produced by exposure 

 to intense cold, a shower of rain, getting the feet 

 wet, or sitting in a cold room all of which are 

 owing either to an imperfect supply of the ani- 

 mating principle by respiration, or to its abstrac- 

 tion from the surface. 



Among all the wonderful adaptations of nature, 

 there is nothing more calculated to excite ad- 

 miration, delight, and gratitude, than the beau- 

 tiful and harmonious dependence of plants and 

 animals on each other, for the well being of both. 



