CAUSES OF DISEASE. 21 



any specific or non-specific agent. Some specific 

 agents only give rise to local infectious diseases (toxae- 

 mias), while others only to septicaemias (or bacteriae- 

 mias). Typical examples of toxaemias due to specific 

 agents are furnished by diphtheria, tetanus (lock-jaw), 

 rabies (hydrophobia), and cholera; of septicaemias 

 (or bacteriaemias), by anthrax, typhoid fever, relapsing 

 fever, bubonic plague, influenza (La grippe), malta 

 fever, etc. Besides the diseases here given, there are 

 many others on the border-line between toxaemias and 

 septicaemias, that is to say, the infection may be local- 

 ized, yet there is a distinct tendency for the infectious 

 agents to invade the blood. Such a disease is pneu- 

 monia which, while it is often an infection localized 

 in the lungs, occurs in a form (croupous) in which the 

 pneumococci which cause it are found in the blood in 

 about ninety per cent of the cases. Pulmonary tuber- 

 culosis (consumption) is another case in point; the 

 disease may remain localized in the lungs for months 

 and even years, yet the specific bacilli often invade the 

 economy. When they do, the germs are distributed 

 everywhere, and a rapid termination of life results. 

 This form of tuberculosis, called by the profession 

 acute miliary tuberculosis, is well known to the laity 

 under the name of rapid, galloping, or quick, consump- 

 tion. 



There is another word in current use in medicine 

 that requires explanation in this place, viz., pyaemia. 



