AUTOLYSIS EXPERIMENTS 77 



Only within the last few years has this difficulty come to be 

 definitely realized and technically avoided,- thanks to the 

 studies of Salkowski and his pupils. 3 For instance, it might 

 be supposed that when a finely divided organ is undergoing 

 autodigestion in a medium well saturated with chloroform 

 and toluol, there would be no danger of the unwelcome pres- 

 ence of bacteria. In actual practice, however, such exact 

 care has by no means been insisted upon ; and it has usually 

 been supposed that if a few drops of toluol or a few bits of 

 thymol were added to a thick emulsion of some organ it would 

 be quite safe to let it stand in the incubator for some months 

 and that the danger of bacterial invasion would be surely and 

 for all time eliminated by such a purely symbolic perform- 

 ance (for that is actually about all it represents) . It is quite 

 obvious why ' ' discoveries ' ' prospered and multiplied in our 

 literature on the same scale as did the bacteria in the pots 

 and jars of the experimenters. But in addition, even with 

 precautions to avoid such gross technical faults, other dif- 

 ficulties often arose in the way of microbic contaminations. 

 H. C. Jackson 4 pointed out that fresh canine livers even if 

 removed with the utmost precaution are rarely entirely 

 sterile, but are apt to contain an anaerobic organism similar 

 to the hay bacillus which does not grow on the ordinary 

 culture media but which grows readily in "sterile" tissues. 

 Jackson believes that the appearance of lactic acid, succinic 

 acid, butyric acid, hydrogen and sulphuretted hydrogen (as 

 noted, for example, by Magnus-Levy in "aseptic autolysis," 

 and their origin referred by him to the corporeal carbohy- 

 drates and fats) is due to the presence of microorganisms in 

 the autolysing mixtures. Here again we are confronted with 

 that intolerable dilemma besetting every point and every side 

 of the chemistry of fermentation : either we are destroying 

 the normal physiological course of the processes by introduc- 



3 E. Salkowski, Yoshimoto, Kikkoji and others, Zeitschr. f . physiol. Chem., 

 3, 109, 1036, 1909. 



4 H. C. Jackson, Journ. of Med. Research, 21, 281, 1909. 



