4 Veterinary Medicine. 



blood was harmless to the rabbit, while one tenth of a drop killed 

 in one hundred and twenty-five hours, and a syringe full in forty 

 hours. 



In ordinary cases of pyaemia the occurrence of internal phlebitis 

 or arteritis with the inevitable thrombosis is an important step in 

 causation. Any inflamation of the inner coat of the vessel leads 

 promptly to the formation of a coagulation of the contained blood, 

 and blocking of the lumen. Beginning on the diseased or 

 abraded surface, the clot forms backward along the line from 

 which the blood normally comes (proximal in the arteries ; distal, 

 in the veins), until it reaches the next considerable colateral 

 branch. The clot is firmly adherent to the intima except at the 

 free end, which is conical and projects into the blood current. 



If small portions are detached from the thrombus and washed 

 on in the blood stream they become arrested when they reach a 

 vessel too small to admit them, it may be a smaller artery, or it 

 may be a capillary, and always in the line of the circulation, — 

 from the systemic circulation to the lungs, or from the lungs to 

 the system at large. This is embolism. Wherever arrested, the 

 contact of the leucocytes and haematoblasts with the inner coat of 

 the vessel, leads to metabolic changes and firm adhesion, and the 

 pus microbes in the clot determine suppuration and abscess. 



Eberth and Schimmelbusch have shown that the haematoblasts, 

 even more than the other blood elements, when acted on by the 

 pus microbes become viscous and stick not only to each other, 

 but to any floating body, and to the inner serous coat of the 

 vessel, particularly when the latter has been abraded or injured. 

 This clumping together of the haematoblasts forms white clots 

 which block the smaller vessels, but in the viscous condition they 

 further the coagulation of the fibriue, and again when they come in 

 contact with the intima, instead of passing through, or moving on, 

 they remain adherent and start the formation of thrombi. This 

 is above all common in given tissues, and the medulla of bone 

 has in this respect a bad preeminence, so that acute suppurative 

 osteomyelitis, is a familiar lesion and is liable to become chronic, 

 and determine distant abscesses and general infection long after. 



The thrombus thus formed is an infective coagulum, tending 

 to constant encrease, as the clot is a favorable culture-field for 

 the microbes, and the tendency is to coagulate more and more of 



