CHAPTER VI 



THE BACTEEICIDAL PEOPEKTIES OF BLOOD SEKUM, 

 CYTOLYSIS, AND SENSITIZATIO1ST 



IN spite of the profound physiological alteration of the animal 

 body which is implied by the acquisition of immunity against any 

 particular infection, we have seen that no anatomical or histological 

 changes in the organs and tissues accompany such alteration. The 

 same is true of the difference between animals of different species, 

 in which the most marked variation in resistance against any given 

 infection is inexplicable on the basis of structural or microscopic 

 characteristics in the organs. We have mentioned briefly the at- 

 tempts that have been made to discover chemical and physical changes 

 or differences to account for such conditions and have seen that the 

 attention of investigators was soon attracted to the blood. 



A possible relationship between the blood and the defence of the 

 body against infection had been foreshadowed by observations made" 

 long before the days of bacteriological knowledge. As early as 1792, 

 John Hunter, in his " Treatise on the Blood, Inflammation and Gun- 

 shot Wounds," had noted that the blood did not decompose as readily 

 as other putrescible material, and a century later, during the period 

 of great interest in the living nature of fermentation and putrefac- 

 tion, Traube (1874) expressed the opinion that blood could destroy 

 bacteria. Similar observations were made by Lister and by Groh- 

 man 1 but no experimental work aimed at this point was carried on 

 until 1886, when the subject was taken up by Nuttall, 2 von Fodor, 3 

 and Fliigge, and a little later by Buchner. 4 These authors, working 

 with defibrinated blood, peptone blood, and blood serum, showed that 

 such substances all exerted a definitely measurable destructive influ- 

 ence upon bacteria, and Nuttall, later confirmed by Buchner, further 

 found that this bactericidal power was weakened on standing, and 

 could be rapidly destroyed by heating to 60 C. 



Their method of procedure consisted in the planting of controlled 

 amounts of various bacteria in measured quantities of blood and, 



1 Grohman. Quoted from Adami, "Principles of Pathology," Vol. 1, p. 

 497. 



2 Nuttall. Zeitschr. f. Hyg., 4, 1888. 



3 Von Fodor. Deutsche med. Woch., 1887. 



4 Buchner. Centralbl. f. Bakt., Vol. 5, 1889. 



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