1 6 PHARMACEUTICAL BACTERIOLOGY 



Period V 



From Behring (1890) to Wright (1907). (Discovery of serum therapy, 

 bacterial vaccines, and development of utilitarian bacteriology.) 



The subject of immunity from disease received early attention. Age 

 immunity, race immunity, animal immunity, individual immunity, artifi- 

 cial immunity, natural immunity, acquired immunity, etc., attracted 

 attention and received careful consideration. Metchnikoff (1884) ex- 

 plained immunity on the supposition that certain white corpuscles (leuco- 

 cytes, phagocytes) of the blood devoured the microbes which entered the 

 system. These white blood corpuscles are the guardians of health. They 

 attack and feed upon any disease germs which may enter the body, either 

 via the digestive tract, the respiratory tract, or via the circulatory system. 

 If the leucocytes are deficient in number, or if the microbes are excessive 

 in number, disease will develop. This theory had numerous followers, as 

 well as opponents. It is now generally accepted as correct, borne out by 

 observation and by experimental evidence. 



The next important discovery was that blood serum had bactericidal 

 properties in a varying degree, and that in addition to this there was some- 

 thing in the blood which had a tendency to neutralize or destroy the action 

 of the poisons or toxins formed by pathogenic microbes. No one par- 

 ticular bacteriologist can be said to have made these discoveries. We can 

 only name a few of the leading investigators who worked along these lines, 

 leading to the discovery of the relationship of immunity and antitoxins 

 Behring, Brieger, Buchner, Calmette, Chamberland, Ehrlich, Emmerich, 

 Fliigge, Frankel, Hiieppe, Jetter, Kitasato, Klemperer, Loffler, Rankin, 

 Roux, Wassermann, and others. These eminent authorities have demon- 

 strated the possibility of developing or aiding the antitoxic or immunizing 

 power of the blood or of the body cells by introducing sera obtained from 

 the blood of animals in which the antitoxic power is naturally high or is 

 made so as the result of special treatment. Numerous sera (containing 

 antitoxins and toxins) were tried ; the one which first proved entirely satis- 

 factory was the diphtheria antitoxin of Behring, which is now in universal 

 use. Others are used more or less successfully, and some are still in the 

 experimental stage. 



In 1890 Koch reported on a "lymph" to be used in the treatment of 

 tuberculosis. This lymph was a glycerin extract of the toxin of the bacillus 

 of tuberculosis, and was to be used in the treatment of this dread disease, 

 but the hopes of Koch were not realized, as the remedy proved a failure, 

 and it soon fell into disuse, to be again taken up very recently. In 1907 

 Wright made knownhi s discovery of opsonins. According to this authority, 

 there exist in the blood certain substances which have the power of acting 



