INFECTION. 35 



stances, however, teach that the distinction between toxic 

 and infectious diseases is not absolute, but only relative. 

 Pneumonia is not unattended with constitutional symptoms 

 (fever, albuminuria, etc.) due to the absorption of the bac- 

 terial toxins circulating in the blood ; and, also, the pro- 

 found symptoms of the algid stage of cholera are only 

 explicable on the assumption of a poison generated by the 

 vibrios in the intestine, and thence absorbed into the circu- 

 lation. Even in the true septicemias the disease and death 

 are ultimately not alone caused mechanically by the indefi- 

 nite multiplication of the bacteria, but here, also, the chemic 

 activity of the bacteria their production of poisons 

 comes into play. Upon the other hand, even in the case 

 of tetanus, the most perfect representative of the toxic in- 

 fections, it has been demonstrated that the influence of 

 bacterial'multiplication in the course of natural infection is 

 not entirely wanting. The multiplication of the germs, 

 however, is quite insignificant and transitory, and the re- 

 markable activity of the poison dominates the clinical 

 picture. 



The mechanical factor plays a much more important role 

 in so-called pyemia than in the case of septicemia. In 

 the former condition the bacteria generally pyogenic 

 microorganisms or those inducing inflammation likewise 

 gain entrance into the blood, by way of the lymphatic chan- 

 nels, from a local, primary focus of disease. They do not, 

 however, become generalized, but remain within certain 

 organs, at times in the serous membranes, at other times in 

 the joints, at yet other times in the skin, in the liver, the 

 spleen, the kidneys, the myocardium, etc. The bacterial 

 masses circulating in the blood cause occlusion in larger or 

 smaller arterial areas, and there result in this way infarcts, 

 ischemic softening, abscesses. Pyemia is thus to be consid- 

 ered essentially a consequence of metastases of the causative 

 agents of the disease. In each of the metastases, however, 

 the bacteria again give rise to their toxic products ; which, 

 in turn, contribute to the further course of the disease. 



Perhaps many of the diseases caused by filamentous fungi 

 (mycoses) depend upon purely mechanical lesions, with- 

 out constitutional intoxication of the organism ; but in 

 those diseases caused by bacteria the influence of poison- 

 production is of importance in every case : every infection 

 is attended also with intoxication ; only the more marked 



