612 BACTERIOLOGY. 



third order " are assumed to be concerned ; the heating 

 destroys the " complement," and thereby checks the proc- 

 ess ', but the subsequent addition of the normal serum 

 supplies fresh " complement/' and at once restores the 

 activity of the hsemolyzing receptors. Eighth, if blood 

 containing a hsemolysin or a cytolysin be repeatedly 

 injected into an animal, anti-bodies "antilysins" are 

 formed, and the serum of the animal has the power of 

 robbing a haemolytic serum of its hsemolyzing function 

 if mixed with it in a test-tube. 1 Ninth, if normal blood, 

 jj containing complement, be injected into the same or 

 another species of animal, anticomplement is formed, 



1 It is evident, from what has been said, that the belief in a vital 

 germicidal function possessed by the fluids and tissues of the body 

 is widespread ; is based upon the best of experimental evidence ; 

 and has served as the starting-point for all the important investi- 

 gations that have been instrumental in moulding our present ideas 

 of immunity. Notwithstanding this, one occasionally encounters a 

 dissenter. Baumgarten, in an address before the German Pathological 

 Society at Munich (see Berliner klinische Wochenschrift, 1899, No. 41), 

 made a vigorous attack upon the evidence that has been presented in 

 favor of a vital germicidal function of the blood-serum. He believes 

 the destruction of bacteria observed when they are mixed with blood- 

 serum to be due less to vital than to physical causes. He regards the 

 death of the organisms in fresh serum as the result of disturbances of 

 assimilation and osmosis, consequent upon their sudden transference 

 from the culture-medium, on which they have been accustomed to 

 develop, to an alien medium of different physical and chemical char- 

 acteristics, and not as a result of vital activities exhibited by any of 

 the ingredients of the serum. 



His opinion is based upon the investigations carried on in his labo- 

 ratory by Jetter in 1892 and by Walz in 1899 (see Arbeiten aus dem 

 Path.-Anat. Institut zu Tubingen, Bd. i. and iii.). 



Revolutionary though it may be, this doctrine, coming as it does 

 from so distinguished an authority, must be given due considera- 

 tion. As yet, it has not attracted very general attention ; nor will 

 it, in all probability, until the evidence advanced by Baumgarten 

 has been subjected to careful experimental scrutiny by other com- 

 petent investigators. Until such is the case, the matter may be held 

 tubjudicc. 



