Heemoglobi-fianiia. —^Asotceniia. — Etc. 443 



A. general survey; of the field; shows -that it is not the simple 

 increase of. any normal waste product in the blood which de- 

 termines haemoglobinsemia; and on the other hand the sudden- 

 ness and severity of the attack bears all the marks of a profound 

 poisoning. The nature of the poison has not yet been definitely 

 ascertained, .yet one (Or two hypothesis, may be hazarded, as 

 furnishing a working, theory, in anticipation of the actual 

 demonstration which may be expected in the early future. 



The action of a stable miasm as claimed by some writers is con- 

 tradicted by the fact that the disease does not develop so long as 

 the animal is left to inhale that miasm, and on leaving the stable, 

 the life and vigor are usually remarkable. 



The morbific .agent must be sought in some source from which 

 it can be supplied with great rapidity under the stimulus of a 

 short but active exertion. The chylopoietic viscera furnish such- 

 a source. The healthy liver contains one-fourth of the entire mass 

 of the blood. The torpid congested liver of the vigorous high con- 

 ditioned horse, after a short period of idleness, on full, rich feed- 

 ing, must hold much more than this normal ratio. The spleen, 

 the natural store-house or. safety-valve of the portal veins, is also 

 gorged with this liquid in the high fed, idle animal. This organ 

 which is alwayg turgescent after meals, is especially so in the 

 over-fed horse, which for twenty-four hours has been denied the 

 opportunity of working off by exercise, the superfluous products 

 of an active digestion and absorption. Then the whole of the por- 

 tal veins.aud the capillaries in which they originate are .surcharged 

 with rich blood which cannot make its way with the necessary 

 dispatch through the inactive liver. 



In this condition there is incomparably more than a quarter of 

 the entire ma.ss of blood, enriched to the highe.st degree in pro- 

 teids, ready to be discharged through the liver and hepatic veins 

 into the general circulation. Under the action of the hurried 

 breathing and circulation, caused by the sudden and active exer- 

 tion, this whole mass of rich blood is speedily unloaded on the 

 right heart, the lungs and the .systemic circulation. One can 

 hardly conceive of a more effective method of inducing a sudden 

 plethora, with an excess of both globules and albuminoids. 



The presence of actual poiisons in such blood is not so easily 

 certified. 



