602 JOHN WEINZIRL 



Miss Hill also isolated a second gas-forming anaerobe which 

 apparently did not form spores and which soon died out in her 

 cultures, thus preventing identification or further study. In 

 our earlier and later studies this organism has not been found. 

 Yeasts were found in some of the chocolates in one lot, but since 

 the candies were badly broken the yeasts were assumed to be- 

 possible contaminations and were not studied further. Aero- 

 bic gas-formers of the Bad. coli type were never found although 

 lactose litmus agar plates were repeatedly made from the fer- 

 mentation tubes. 



It was noted above that one lot of cracked chocolates never 

 gave gas-formers when inoculated into glucose Smith tubes 

 which were freshly boiled to drive out absorbed oxygen, and 

 which contained a piece of meat to promote anaerobiosis. The 

 writer has since received another lot of candies which contained 

 cherry centers and showed cracking. When tested as before, 

 these failed to show gas-forming bacteria. The cherries taken 

 from the barrel also failed to show gas formers. Apparently 

 the cracking of chocolates may at times be due to non-bacterial 

 causes, and in the above case this cause seemed quite clearly 

 to be rough handling by the employes. 



It is possible that expansion due to increased temperature 

 may also cause cracking, but we have no evidence for this; we 

 know, however, that normally a chocolate slowly loses its mois- 

 ture content and this would tend to prevent cracking. Appar- 

 ently true explosions in chocolates are always due to the accumu- 

 lation of gases formed by fermentative microorganisms. 



INOCULATION EXPERIMENTS 



Thus far the evidence strongly favors the conclusion that 

 gas-forming anaerobes cause the explosion of chocolates. To 

 make the conclusion certain, inoculation experiments were 

 carried out. These experiments were performed in two ways. 

 In the first trial, various kinds of chocolates were secured, small 

 holes drilled through the coating, and a culture of B. sporogenes 

 was inoculated into the fondant through this hole by means of a 



