100 BOVINE PATHOLOGY. 



to have a special power of disintegrating red globules. 

 Under certain circumstances the red colouring matter be- 

 comes dissolved in the surrounding serum, which stains 

 the walls of the blood-vessels. This occurs, more or less, 

 in all cases of stasis or extravasation of red corpuscles, 

 but especially from certain chemical changes in the 

 serum, as admixture of bile salts. As potash and phos- 

 phates occur particularly in the corpuscles, while sodium 

 and chlorides are mainly in the serum, we can see that 

 various foods are adapted especially for the formation of 

 special parts of the blood. 



(j3) Eetention of matter in the blood which should be 

 excreted. 



There are certain organs which remove effete matter 

 from the blood. Of these the principal are lungs, liver, 

 skin, and kidneys. If either of these organs act im- 

 perfectly, and the others are unable by vicarious action to 

 perform its duties with suflScient energy, accumulation 

 of effete matter leads to blood disease. 



Carbonic Anhydride poisoning results from defective 

 action of the lungs. It may also take place from exposure 

 to an atmosphere containing excess of this gas, as the 

 '^ choke damp ^' generated by explosions in mines. The 

 fact that a chronic form, as it were, of this disorder 

 results from imperfect escape of foul air from cow-houses 

 must make us attend to due ventilation. This chronic 

 state predisposes to disease of a low type, lessening con- 

 stitutional vigour. Thus, 3 per cent, of this gas in the air 

 lessens the frequency of the pulse and increases the respira- 

 tions ; 1'5 — 2 per cent, suffices to produce headache in man, 

 and fatal results ensue on exposure to air containing 5 — 10 

 per cent. The severity of disorders of the lungs is consider- 

 ably increased by the accumulation of carbonic anhydride 

 in the blood which results from them. This substance 

 acts as a narcotic poison. Acute cases of carbonic acid 

 poisoning are manifested by laboured breathing and other 

 signs of narcosis, ultimately leading to death from 

 asthenia. 



Treatment must consist in exposure to fresh air, ad- 



