1891.] ♦ on Infectious Diseases, 287 



this unfavourable condition can be altered in a variety of ways, e.g. 

 temperature, muscular fatigue, sugar in the tissues, &c. But also a 

 primary favourable condition can be rendered unfavourable : for 

 instance, a human being that has passed through one attack of 

 scarlatina offers tissues unfavourable for the growth of scarlatina 

 microbes ; attenuated anthrax protects against virulent anthrax ; an 

 animal that has been first treated with repeated small doses of the 

 chemical products of a peculiar microbe becomes unsusceptible to 

 that microbe. 



In order to explain the whole group of phenomena of refractory 

 state, immunity, and protection, a theory has been put forward which 

 is as simple as it is fascinating. There can be truly no greater 

 satisfaction and no greater aim in any branch of science than to 

 express a great number of facts and phenomena by the simplest 

 possible formula ; the greatest minds and the most successful philo- 

 sophers have achieved this. Now, in regard to the numerous and 

 extremely complex phenomena that we have under consideration, a 

 simple formula has been put forward which is supposed to cover all 

 the facts and to explain all the phenomena ; this formula is comprised 

 in a single word, " phagocyte." This word is put forth whenever 

 and wherever a difficulty arises in explaining or understanding the 

 complex problems involved in the intimate pathological processes, 

 the refractory condition, the unsusceptibility to and immunity from 

 an infectious disease. To any and every question referring to infec- 

 tious diseases the answer is simply " phagocyte." By a " phagocyte " 

 is understood one of those elementary microscopic corpuscles abound- 

 ing in the animal and human body, possessed of spontaneous or 

 amoeboid movement, and occurring in the blood as white blood-cells 

 or leucocytes ; in the lymph and lymph-glands and most tissues, as 

 lymph corpuscles ; in all acute and chronic pathological processes, as 

 pus-cells or round cells. The cells, by their protoplasmic or 

 amoeboid movement, have the power to take up into their interior all 

 manner of minute particles or granules, living or non-living; it 

 seems as if these granules and particles were being swallowed up, 

 eaten, and destroyed by the cells — hence the name of eating globule, 

 or " phagocyte," given to them. 



These cells — white blood-cells, lymph-cells, or round cells — are 

 supposed to have the important function to act as the sanitary police 

 against the invading Bacteria, to be always on the look-out for them, 

 and where they meet them to at once engage in battle with them • 

 that is to say, to do as the giants do — to eat their victims. If the 

 phagocytes are victorious — that is, if they succeed in eating up the 

 Bacteria — no harm is done to the animal body ; no disease is pro- 

 duced ; but if, for one reason or another, the Bacteria succeed in 

 evading the grasp of the phagocyte police, then the Bacteria grow and 

 multiply, and cause the disease. Sometimes this latter result follows 

 on account of the phagocytes not being capable of moving sufficiently 

 briskly to the places of mischief, or, for some inherent reason, not 



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