AETIFICIAL PEODUCTION IN ANIMALS. 125 



9 



region. A large abscess was found at the point of injection and 

 numerous metastatic abscesses in the internal organs. In the pus 

 of these abscesses he found a micrococcus which he considered as 

 characteristic of this affection. 



Klein (Microorganisms and Disease, 1885) described a micro- 

 coccus of pyaemia in mice. Certain cocci which were present in 

 pork-broth proved fatal to mice in about a week, producing puru- 

 lent inflammation at the point of injection and metastatic abscesses 

 in the lungs. Fresh inoculations in mice again produced a fatal 

 result with pyaemic symptoms. 



Pawlowsky found that, by the simultaneous injection of sterilized 

 cinnabar, and of cultivations of staphylococcus pyogenes aureus 

 into the circulation, he produced abscesses in various organs in 

 fact, the typical picture of pyaemia. The presence of particles of 

 foreign bodies rendered material aid in the development of metas- 

 tatic abscesses, as the mere arrest of pus-microbes in the circulation 

 without them, as a rule, is not sufficient of itself to lead to the 

 production of true pyaemia. In rabbits, even the introduction of 

 a large quantity of a culture of pus-microbes into the circulation 

 does not produce pyaemia. Twenty-four hours after the injection 

 the microbes may be found in large numbers in the pulmonary and 

 other capillaries, but after forty-eight hours they have all disap- 

 peared from the circulation. If the cocci are suspended in an 

 embolus, this latter, by producing alterations in the endothelia of 

 the bloodvessels in which it has become impacted produces a locus 

 minoris resistentice favorable to the growth of germs. In the ex- 

 periments of Pawlowsky, the particles of cinnabar acted upon the en- 

 dothelia lining the capillary vessels in the same manner as the frag- 

 ments of a thrombus by impairing the local nutrition of the tissues 

 at the point of impaction. If pyaemia is produced in guinea-pigs, 

 or mice, with infectious pus, or with a pure cultivation of the same, 

 the same local conditions are produced which invariably precede 

 the development of pyaemia in man. Some of the veins at the 

 seat of primary infection are invaded by pus-microbes and become 

 blocked by a thrombus, this thrombus undergoes puriform soften- 

 ing, small fragments containing pus-microbes become detached, 

 and are washed away and enter the general circulation as emboli, 

 which, when they become arrested, establish independent centres 

 of suppuration. In such cases the pus-microbes are present in 

 the blood, in the tissues around the abscess, and in all purulent 

 collections. 



